Bulletin of the American Physical Society
APS March Meeting 2020
Volume 65, Number 1
Monday–Friday, March 2–6, 2020; Denver, Colorado
Session C71: Poster Session I (2:00pm  5:00pm)Education Poster Undergrad Friendly

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Room: Exhibit Hall C/D 

C71.00001: UNDERGRADUATE RESEARCH


C71.00002: Using GALFIT to Determine Galaxy Morphologies of Quasars Kaitlyn Raub, Mariana Lazarova, Gabriele Canalizo, Mark Lacy Little is known about the morphologies of quasars. Quasars are the brightest of the active galaxies, in which a supermassive black hole is accreting material, creating an accretion disk that outshines the host galaxy. We model images obtained from the Hubble Space Telescope of 22 nearby quasars and the galaxies in their immediate neighborhood using the GALFIT software to determine how well they are fit by typical galaxy profiles. GALFIT is an image analysis algorithm which fits parametric functions to create light profiles from twodimensional images. We fit the quasars using two main components  a Point Spread Function (PSF), which represents a point source object (the light of the accretion disk), and a Sérsic profile, which models galaxy structures, such as a disk or a bulge. We will present details on the models, including the types of components used in each fit as well as the residual maps after subtracting the model from the data. 

C71.00003: SuperCDMS: Energy Calibration of a Cryogenic Ge HV Particle Detector Salamong Xiong The goal of the SuperCDMS collaboration is to directly detect dark matter. Potential candidates for dark matter are Weakly Interacting Massive Particles (WIMPs). To detect WIMPs, it is important to be able to predict how a Ge/Si particle detector will respond to a dark matter signal. In particular, it is necessary to calibrate the recoil energy measured by these detectors. This paper presents the energy calibration spectrum of a SuperCDMSHV Ge particle detector using Am241 and a PuBe neutron source. Due to high event rate, criteria were developed to remove lowquality data arising from particle interactions that occur too soon after a previous interaction. Peaks in histograms of pulse amplitudes were identified as energy peaks from the various radioactive sources, and fits of these peaks formed the basis for generating an energy calibration function. The calibration function was used to generate the calibrated energy spectrum. 

C71.00004: Effect of polyethylene oxide on camphor sulfonic acid doped polyaniline thin film field effect transistor with ionic liquid gating Luis M Rijos, Anamaris Melendez, Rolando Oyola, Nicholas Pinto Field effect transistors (FET) using camphor sulfonic acid (CSA) doped polyaniline (PANi) blended with several polyethylene oxide (PEO) concentrations were investigated via ionic liquid gating. The pure PANiCSA FET could not be turned “off” and had an on/off ratio of 2. Blending with 22wt%PEO retained a high “on” state throughput current and improved the mobility, while the on/off ratio increased by 10^{3}. Superior film quality and PEO assisted electrostatic long range interactions with the PANi chains led to device parameter enhancement. For higher PEO concentrations the field effect was suppressed due to disorder. Analysis of the UV/Vis spectra polaron band peak area near 810 nm show an increase in the mobility with decrease in the peak area, consistent with the observed results. Enhanced device parameters, high throughput current and low operating voltages (±2V), make PANiCSA/PEO blends attractive materials for use in low power consumption electronics. 

C71.00005: Fabrication of femtosecond laserinduced crystals in lithium nioboSilicate 30: the effects of polarization angle on orientation and growth rate. Rutendo jakachira, Courtney Auyeung, Evan Musterman, Himanshu Jain


C71.00006: Ultrasonic Acoustic Probing Based on Gaussian Beam Analysis Emily LaPrime, Sanichiro Yoshida By analyzing differences in phase and amplitude of a signal, information about differing acoustic contrast between materials can be quantified. Prior methods used a scanning acoustic microscope which allowed for phase shifts to be identified by reflections but could not quantify phase shifts besides 0° or 180°. The new method uses a continuous signal to identify more precisely the phase and amplitude to analyze the transmitted signal. We have utilized the knowledge that the acoustic signal used behaves as a Gaussian beam travelling through a material. As the beam comes into contact with a defect, it is theorized to split into multiple source waves on either side which interfere as they travel across the plate to the receiver. By keeping the transmitter stationary and probing the receiver, we examine how the phase and amplitude change as the distance between transducers varies (transverse profiles). This approach potentially has a biological application because the acoustic contrast between healthy cells and cancerous cells is difficult to identify using current ultrasonic methods. This testing method could potentially gather more precise data with respect to the slightly differing contrasts between the cells and help better identify the presence and location of unhealthy cells. 

C71.00007: Quantum Key Distribution Using Optimum Expectation Values of Maximally Entangled GHZ States collin kessinger, Ye Jin Han, Qiaoren Wang We propose a new quantum key distribution scheme that is based on the optimum expectation values of maximally entangled GreenbergerHorneZeilinger states. Our protocol makes use of the degrees of freedom in continuously variable angles, thereby increasing the security of the key distribution. Outlined are two protocols that distribute a key from Alice to Bob using the above idea, followed by an extension that allows for the same key to be shared with Charlie. We show how this scheme provides for certain detection of any eavesdropper through absolute violation rather than the probabilistic violation used in many protocols. 

C71.00008: Temperature dependent charge transport in graphene with ferroelectric gating Kelotchi Figueroa, Luis M Rijos, Nicholas Pinto, Srinivas Mandyam, Mengqiang Zhao, Alan T Johnson CVD graphene was electrically characterized in a field effect transistor configuration with ferroelectric (FE) gating in the temperature range 300K < T < 350K. Saturated hysteresis loops of the FE copolymer poly(vinylidene fluoridetrifluoroethylene)PVDFTrFE(75/25) showed that the memory window width decreased as temperature increased. Device transconductance (IVg) curves exhibit hysteresis behavior with two charge neutrality points (CNP) corresponding to the up/down polarization of the ferroelectric gate. Increasing the temperature decreased the change of the gate voltage and increased the change in the channel current measured between the two CNP’s. The electron mobility showed a steeper decrease compared to the hole mobility as temperature was increased. Desorption of O_{2} and H_{2}O was used to explain these observations. Finally, nonvolatile switching was realized using the charge storage property of the gate insulator. 

C71.00009: Developing a Method for Measuring the Optical Scattering of Silica Nanosprings Jeffrey Yoder, David N McIlroy Nanosprings have been shown to have a variety of applications in medicine, industry and material science due to their unique nanoscale characteristics. Recent developments have vastly improved the ability to produce large quantities of highquality silica nanosprings, making possible new avenues of research and applications. Current research includes applications in prostheticbone interfaces, detection of small quantities of gases, and the development of new composite materials. As such, there is a growing interest in better understanding their properties. The motivation for this work is to develop a method for studying the optical properties of these silica nanosprings. An apparatus for measuring the optical scattering of light off of the nanosprings has been constructed and measurements are ongoing. The first objective is to confirm visual observation of diffraction effects in nanosprings. The apparatus uses a visual microscope, a spectrograph, and illumination by a variety of lamps via fiber optics. A single nanospring is held by a micromanipulator; light (typically white) is then scattered off the spring and collected to produce spectra. This data is then analyzed for diffraction effects. 

C71.00010: PhaseModulated Local Oscillator Effects on RFDNA Fingerprints in IEEE 802.11a WiFi Signals William Mitchell, Kaitlin Hall, Ahmed Ibrahim `, Donald Reising, Thomas Daniel Loveless With the increasing dependence on the internet in more and more consumer products, there is an urgent need to enhance existing digital security systems. RFDNA fingerprints are one such approach to utilize discriminating waveform characteristics to augment the detection (rejection) of approved (unapproved) WiFi devices. This work investigates a timedependent approach to manipulate the RFDNA fingerprints of a transmitting device through local oscillator phase modulation of the clocking system in WiFi transmitters. Experimental results are used to investigate the ability for an unaffected receiver to detect a corresponding clockmodulated transmitter, as well as the changes of 802.11a WiFi preambles of clock phase modulated transmissions. Changes in the waveforms are further analyzed using the Discrete Gabor Transform in the timefrequency domain. Analysis shows a predictable pattern of change over time, proportional in frequency to the phasemodulation frequency, and the ability for preamble structures to remain intact up to 30 kHz of phase modulation. 

C71.00011: Investigation of the Damage to Hydrophobic SelfAssembled Monolayers by Aqueous Salt Solutions Juliana Sebolt, Cayton Hornberger, Grace Rohaley, Adele Poynor When water is forced into contact with a hydrophobic surface, a depletion layer, or a lowdensity region of water, is formed. To study the depletion layer in more natural applications, we look at how aqueous salt solutions interact with hydrophobic surfaces made from selfassembled monolayers (SAMs) of octadecanethiol. In order to investigate this interaction we need smooth, homogeneous SAMs. Aqueous solutions can corrode the SAM, so we experiment salt molarity and cation size to eliminate this problem. The experimental methods include contact angle measurements, scanning electron microscopy, surface plasmon resonance. 

C71.00012: Optimization of Microgel Imaging Using SEM Samantha C Tietjen, Petru Stefan Fodor, Kiril Streletzky Microgels are polymerbased nanoparticles suspended in water that exhibit. The standard, noninvasive method for characterizing microgels is dynamic light scattering (DLS), which measures collective diffusion of microgels. While DLS provides reliable estimates for particle structure/dynamics, more direct methods of imaging are useful for studying polydisperse samples. Traditionally, scanning electron microscopy (SEM) uses an electron beam under high vacuum to characterize individual dried particles of dried. The dry microgel imaging suffers from two drawbacks: dehydrated particles collapse under vacuum and their dynamics is not observable. This project explored wet particle imaging in an ionic liquid stable under high vacuum. Particles were suspended in an ionic liquid film on a copper grid. Still images/movies were recorded to analyze microgel size distribution and dynamics. The average SEM size generally agreed with DLS both in ionic liquid and in water at room temperature. Variation was observed in individual particle sizes, but the average SEM size for both samples were close to the DLS size. Initial attempts at diffusion analysis using SEM particle tracking yielded mixed results as it requires tracing of many particles and further optimization. 

C71.00013: Effect of cerium substitution on the superconducting state of Ba_{0.6}K_{0.4}BiO_{3} Mohamed Essam Nawwar, Benjamin White The superconducting compound Ba_{0.6}K_{0.4}BiO_{3} has one of the highest critical temperatures (T_{c }= 30 K) of any noncuprate oxide. In this study, we probed its superconducting properties by studying the impact of chemical substitution with Ce on the system Ba_{0.6x}Ce_{x}K_{0.4}BiO_{3}. The objective of this study was to measure the effect of introducing magnetic moments by comparing the xdependence of T_{c} in Ba_{0.6x}Ce_{x}K_{0.4}BiO_{3} with the previously established behavior of Ba_{0.6x}La_{x}K_{0.4}BiO_{3}. Our polycrystalline samples, synthesized using the molten salt technique, exhibited suppressed T_{c} values compared with that of Ba_{0.6}K_{0.4}BiO_{3}; however, we were unable to observe a clear correlation between measured lattice parameter values and x, suggesting that the molten salt synthesis method we used is unable to finely control the Ce content of the samples. Additional measurements will be required to determine the exact stoichiometry of the samples and xray photoemission spectroscopy will be required to determine the oxidation state of Ce ions. In this poster, xray diffraction and magnetic susceptibility measurements will be presented and compared with results from Ba_{0.6x}La_{x}K_{0.4}BiO_{3}. 

C71.00014: Fragmentation and Desorption of SurfaceImmobilized DNA on PMMA and PAA Substrates for Sequencing Applications Ellen Guo, Qinxi Liu, Kathy Xing, Kerui Yang, Luisa Pan, Jocelyn Zhu, Anthony Del Valle, Joseph Jennings, Jonathan Carl Sokolov


C71.00015: Observation on WSe_{2}/WS_{2} heterobilayer spectroscopic and transport features Zhuohang Yu, Felipe Cervantes Sodi, Nestor Perea Lopez, Ana Laura Elias Arriaga, Tianyi Zhang, Mauricio Terrones Semiconducting transition metal dichalcogenide (TMD) monolayers are one of the most promising materials for future optoelectronics. When two different TMD monolayers are brought together, the interlayer electronic coupling effects generate a new band structure inherent to the bilayer. We aim to fabricate heterobilayers comprising WSe_{2} monolayer and WS_{2} monolayer and analyze their optical spectroscopic and electronic transport features. 

C71.00016: Investigation of Track Formation in CR39 for Various Hydrated Enviornments. Micah Karahadian, Austin R Smith, Emma Vahle, Heide M Doss CR39, a thermoset resin, is a well characterized integrative detector that, when etched, shows tracks created by energetic charged particles produced in nuclear reactions. It has been questioned whether this detection method can be used in Pd/D electrolytic cell environments. Of concern is whether the pyrophoric nature of hydrogen’s interaction with palladium and its recombination with oxygen within the cell can create similar tracks. The validity of this detection method in an electrolytic cell environment is investigated. Additionally, track comparisons from detectors used in a Pd/D codeposition experiments utilizing K40 or Li6 electrolytes were done to determine if Li6 contributes to the observed tracks. 

C71.00017: Topological Effects in Knotted Arrays of OneDimensional Quantum Rings Colin Riggert, Kieran Mullen Quantum ring arrays (QRAs) offer insight into the impact of topology in quantum systems, displaying phenomena which often have implications in quantum technology. We study the energy spectra and wavefunction behavior of small (two and three ring) QRAs by building up a model of tunnelcoupled onedimensional quantum rings from existing models of crossed onedimensional quantum wires. An ambiguity arises in how we connect the ends of these crossed wires, allowing us to create QRAs with the same tunnel coupling, but topologically distinct boundary conditions. We solve these systems numerically for various strengths of the tunnel coupling and find that topological differences in hole count manifest in observable differences in the single electron QRA energy spectrum in the absence of external fields. We also consider these QRAs in the presence of a uniform external magnetic field that induces an AharonovBohm phase in the electron as it tunnels. By varying the induced phase, we explore magnetic phase commensuration effects in the QRA energy spectra and find that these QRAs have additional topological qualities that manifest in further differences in the energy spectra. We propose knot theory as the tool for distinguishing these systems and explaining phase commensuration effects. 

C71.00018: Effect of transverse magnetic fields on an isotopically engineered diamond NV ensemble Jon Campau, Peter Brereton, Rajratan Basu, Danielle Braje The nitrogen vacancy (NV) in diamond is a leading candidate for quantum sensing applications such as magnetometry. Here, we study the effect of a transverse external magnetic field on the spin coherence of an ensemble of nitrogen vacancy (NV) centers in diamond with applications to highsensitivity magnetometry. A transverse magnetic field has been shown to suppress electronic spin decoherence [1]. By utilizing 15N ions for implantation, the nuclear hyperfine interaction between the 13C spin bath and the defects is minimized. We utilize optically detected magnetic resonance and pulsed methods to explore this effect in isotopically engineered diamond films. 

C71.00019: Link Testing between the Data Formatter and Second Stage Boards for the Fast Tracker Trigger in the ATLAS Experiment at CERN Christina Pino At CERN, link testing was performed between the Data Formatter (DF) board and the Second Stage Board (SSB). This was to advance the installation of the Fast Tracker Trigger (FTK) for the ATLAS collaboration by the end of the 2^{nd} Long Shutdown (LS2). Link testing was performed in the Underground Service ATLAS hall (USA 15) where the FTK is located. Different combinations of the Data Formatter board and Second Stage Board were tested using Xilinx’s Integrated Bit Error Ratio Tester (IBERT) to vary the transceiver and receiver settings between the boards. To analyze the bit error ratio between the boards, the IBERT core would generate eye scans and bathtub plots to get a visualization of the digital signal integrity. 

C71.00020: Highly nonstoichiometric amorphous oxide semiconductors: the structure and electronic properties of defects in aInOx Elizabeth CaputaHatley, Julia Medvedeva Oxygen nonstoichiometry in crystalline In2O3 leads to formation of oxygen vacancies that play key role in carrier generation and transport in this transparent conducting oxide and have been wellstudied both theoretically and experimentally. In contrast to the crystalline oxide, the structure and electronic properties of oxygen defects in amorphous indium oxide (aInOx) are not understood and render to be fundamentally different due to the lack of lattice sites and periodicity as well as an increased number of degrees of freedom in disordered materials. Strikingly, the observed carrier concentration in aInOx is two orders of magnitude higher than that in the crystalline oxide. Moreover, given the ionic nature of indiumoxygen bonding, it is possible to grow highly nonstoichiometric amorphous oxides that helps tune the properties over an extremely wide range. 

C71.00021: In situ ellipsometry of epitaxially grown bismuth antimony telluride on sapphire Molly McDonough, Timothy Pillsbury, Anthony R. Richardella, Nitin Samarth Ellipsometry uses elliptically polarized light to characterize thin film and bulk materials. The light undergoes a change in polarization as it interacts with the sample structure. The measurement is typically expressed as two values: Psi (Ψ) and Delta (Δ). Bismuth telluride and its alloys are widely used as materials for thermoelectric and spintronic devices. This project uses in situ rotating compensator spectroscopic ellipsometer to measure properties of Bismuth Antimony Telluride ((BiSb)_{2}Te_{3}). If properties of bismuth antimony telluride such as thickness and composition can be determined by ellipsometry, it can be used as a tool to improve growth parameters in realtime, improving throughput and precision when growing these materials. 

C71.00022: Study of Optical Properties of composite layers of MEHPPV nanopillars and PEDOT:PSS films Evangeline Beeching Fabrication of MEHPPV nanopillars was completed using porous Anodic Aluminium Oxide (AAO) templates. The diameter and height of the nanopillars was controlled by adjusting the dimensions of the template. The morphology of the nanopillars was studied using scanning electron microscopy. The absorption of light of MEHPPV nanopillars plus thin film was greater than that of the thin film only, both being the same thickness.The dimensions of nanopillars are essential for carrier processes such as exciton generation, exciton diffusion and carrier dissociation and transport. As PEDOT: PSS can enhance hole collection and exciton diffusion, addition of PEDOT: PSS improves the performance of solar cells. The variation in optical properties of composite material consisting of MEHPPV nanopillars and PEDOT:PSS films will be investigated using UVVis spectroscopy and fluorescence spectroscopy with change in height and diameters of the MEHPPV nanopillars. 

C71.00023: Modeling directed selfassembly of nanoparticles under perpendicular electric fields Elise Baker, Matthew Withers, Dan Mazilu, Irina Mazilu We design and model an experiment to study the effect of electric bias on particlecoverage densities produced during ionic nanoparticle selfassembly. The experiment involves the application of a uniform external electric field parallel to a glass substrate during the selfassembly of silica nanoparticles. We refer to this procedure as directed selfassembly of monolayers (DSAM). In our theoretical analysis, we modify existing cooperative sequential adsorption models to account for diffusion under an applied electric field. We use the mean field approximation to solve for particlecoverage densities. To ascertain the validity of this method, we compare our solutions to Monte Carlo simulations of the system. We also discuss particular experimental implementations of an ionic selfassembled monolayer under the influence of perpendicular external electric fields. 

C71.00024: Nonlinear Magnon Scattering Observations Via The MagnetoOptical Kerr Effect Paul Bailey, Paul Crowell Nonlinear Magnon Scattering is observed in Yttrium Iron Garnet (YIG) thin films. Nonlinearity is excited in the YIG thin films by high power microwave pumping. The magnetization of the films due to the microwave pumping is then observed through the Magneto Optical Kerr Effect (MOKE). The MOKE is of interest as a measurement technique because of its potential to observe magnon scattering in real time. Welldefined thresholds of the linear and nonlinear regimes are examined by ferromagnetic resonance measurements using this setup. 

C71.00025: Thermal metamorphism study of carbonaceous chondritic meteorites Rohil Kayastha, Raka Paul, Aaron Stokke, Analía Dall'Asén Carbonaceous chondritic meteorites are some of the most primitive materials in our solar system. They did not experience melting or other processes on their parent bodies (e.g. asteroids) during their initial formation, and thus, they preserve information of physical and chemical mechanisms in the solar nebula, which can unveil evidence about the origin of the planets and their components. However, most carbonaceous chondrites are exposed to secondary processes on their parent bodies, such as thermal metamorphism and aqueous alteration, modifying the primary properties of the carbonaceous chondritic constituents. Hence, in order to understand how these relics formed, it is important to analyze the modifications they have experienced induced by these secondary processes. In this work, we study the thermal metamorphism of these chondrites examining their carbon composition by Raman spectroscopy. We analyze the Raman spectra of carbon allotropes to obtain specific parameters that we use for thermal metamorphism mathematical models. In addition, we correlate the Raman results with those acquired using SEM/EDS (Scanning Electron Microscopy/Energy Dispersive Xray Spectroscopy), and we compare these findings with the results obtained from previously studied meteoritic samples. 

C71.00026: Temporal superresolution differential dynamics microscopy for detecting fast dynamics Ruilin You, Ryan J. McGorty


C71.00027: GradientBased Algorithms for Characterizing the Structure of Fibrin Clots Nolan Roth The human body’s ability to close wounds through clotting is vital to everyday function—but irregular clotting can cause diseases like deep vein thrombosis, Von Willebrand disease, or hemophilia, which lead to hundreds of thousands of deaths each year. Understanding how various clotting mechanisms affect the mechanical and structural properties of a blood clot’s fibrin fiber network is integral in working to prevent and treat these clotrelated diseases. Two structural characteristics of the network, the average fiber diameter and branch point density, lend themselves to discovery by applying various computational image analysis techniques to images acquired using scanning electron microscopy or fluorescence microscopy. Algorithms using gradientbased thresholding were implemented in Python to minimize data loss from classic image analysis techniques and to quantify the network’s structural characteristics. 

C71.00028: Progress on the Development of a Magnetic Field Sensor Katherine Gifford, Zoya Shafique, Sean James Bentley This project aims to develop a magnetic field sensor by using the special properties of quantum entangled photons to intensify the sensitivity of a Faraday effect based sensor. The Faraday effect occurs when the polarization of light rotates as it passes through select materials in the presence of a magnetic field. For our set up, we chose crystals with high Verdet constants: Cd0.57Mn0.43Te andCd0.86Mn0.14Te. The introduction of a super magnet creates a measurable polarization rotation in light passing through the selected crystals. Using a magnet in the shape of an annulus, we experimented with a variety of geometrical configurations in an attempt to maximize the rotation produced by the magnet and crystal. In the first set up, we mounted the magnet in close proximity to the crystal. In later designs, we placed the crystal inside of the super magnet by 3D printing a structure to hold the crystal. Generating positionmomentum entangled photons through parametric downconversion, our goal is to use the quantum nature of the photons to create a highly sensitive magnetic field sensor. 

C71.00029: Adsorption of CO_{2} and N_{2} on Graphite and Cone Grid EMILY KOIVU, Silvina Gatica Adsorption is the phenomenon that occurs when a gas is in the presence of any material and is uniquely fit for different elements. Using molecular dynamics simulations, the adsorption of a CO_{2} and N_{2} mixture on graphite is studied at differing temperatures. Attempts to increase selectivity are made by introducing cones, inverted and upright, on top of the graphite. Results show that at molecules are more easily adsorbed at 300K than 400K and that the presence of the cones decreases selectivity, though upright cones perform worse than inverted cones. Further study at different ranges of temperature and strengths of interactions with the inverted cones should provide useful in determining the most effective way to use adsorption to separate CO_{2} and N_{2}. 

C71.00030: The Effect of Si Nanoparticles and SiGe Nanoparticles on the Photovoltaic Conversion Efficiency CdS/CdTe Thin Film Solar Cells Jasmyne Emerson, Yunis Yilmaz, Mehmet Alper Sahiner The addition of embedded Si nanoparticles and SiGe nanoparticles in CdS/CdTe thin films deposited on ITO coated glass has been investigated in this study. We’re testing the effects of Si nanoparticles and SiGe nanoparticles on the efficiency of CdS/ CdTe thin film solar cells and comparing the effects of different deposition times, particles sizes, and how they compare with each other. Si was originally tested in order to compare to the results of Au and Ag nanoparticles. SiGe nanoparticles are also being tested because Ge is likely to form more stable nanoparticles. SiGe alloys will have higher mobility as charge carriers than Si. In the process of creating these solar cells, CdTe and CdS are deposited onto ITO coated glass substrates using the method of Pulsed Laser Deposition. Si or SiGe nanoparticles were deposited between the CdS layer and the CdTe layer using the PLD method with various deposition parameters and durations to obtain variations in nanoparticles coverage at the interface. In order to characterize the Si nanoparticle embedded thin films, XRD, AFM, and SEM/EDX were used. 

C71.00031: Engine of Life: Biophysics and Tyrosine Ji Ku, Deanna Luneau, K. V. Lakshmi Carbon dioxide emissions have increased sharply within the last few decades, which has resulted in climate change and pollution. This has led to the search for alternative energy sources, using photosynthesis as an inspiration. Within photosynthesis, photosystem II (PSII) uses light energy to drive the energetically demanding fourelectron oxidation of water to dioxygen. There are two symmetric redoxactive tyrosine residues, Y_{Z }and Y_{D}, in the D1 and D2 protein subunits of PSII. While these tyrosine residues are chemically identical, they are functionally distinct. It is proposed that Y_{Z }is directly involved in the primary electron transfer pathway of PSII. In contrast, the Y_{D }residue is proposed to be involved in the assembly of the catalytic Mn_{4}Caoxo cluster. My research is focused on understanding the structure and function of the Y_{Z}and Y_{D}residues of PSII. In my presentation, I will describe the methodology of cyanobacterial cell cultures, isolation and purification of PSII and the application of pulsed electron paramagnetic resonance spectroscopy to study the Y_{Z }and Y_{D }radicals of PSII. 

C71.00032: Ideal Diode Behavior at the Graphene  WSe_{2} Schottky Junction Collin Sanborn, Ji Ung Lee The metalsemiconductor interface is a core component of many nanoelectronic devices. The Schottky junction that can form at these interfaces is key to our understanding of device behavior. We have demonstrated that in graphenesilicon junctions, the currentvoltage behavior based on bulk analysis no longer applies, and the diode is best characterized by the Landauer quantum transport formalism. We extend this analysis from silicon to transition metal dichalcogenides, a class of 2D semiconductors. We construct Van der Waals heterostructures of graphene and tungsten diselenide encapsulated in hexagonal Boron Nitride, and vary the geometry to analyze the physics of this new Schottky junction. 

C71.00033: Ferromagnetic Positron Beam Guidance for Single Shot Measurement in 2DACAR Spectrometers Martin Grosshauser Angular correlation of electronpositron annihilation radiation (ACAR) is a technique to determine the electronic structure of solids. It is based on detecting the annihilation gammas' deviation from collinearity in order to measure the electron momentum before annihilation. 

C71.00034: Symmetries of Two Atoms with Contact Interactions in a Ring Trap Isabel Fernandez, Nathan L Harshman We consider an idealized model of ultracold atoms in a ringshaped optical trap with swave and pwave contact interactions. The relative dynamics for two interacting particles are mapped onto a single particle traveling on a ring disrupted by zerorange deltafunction barriers and deltaprime barriers. We categorize the symmetry groups of these potentials and find the exact solutions for stationary states. By classifying the energy spectrum in terms of the irreducible representations of the symmetry groups, we reveal that there are additional symmetries “hidden” in contact interactions. 

C71.00035: Measurements of the Size Variation of Optically Trapped Aerosol Water Droplets Using Cavity Enhanced Raman Spectroscopy (CERS) Dalton Anderson, Lowell I McCann Optical traps have numerous applications including the study of aerosol droplets. It has been observed that in a single beam optical trap, micrometer sized aerosol droplets exhibit hysteric axial motion in the direction of beam propagation. Two metastable positions have been observed and it is thought that the cause of this motion between positions may be due to morphology dependent resonances (MDRs). For this to occur, thermal expansion of the droplet from a varying laser beam power must occur. Using Cavity Enhanced Raman Spectroscopy (CERS) we can investigate the size of the droplet as the position of the droplet and the laser power varied. 

C71.00036: Timeintegrated Fourwave Mixing Measurements on Transition Metal Dichalcogenides in High Magnetic Fields Alejandro Villalobos, Denis Karaiskaj, Stephen A McGill, Varun Mapara Monolayer transition metal dichalcogenides are 2D materials with unique optical properties that make them potential candidates for use in optoelectronic devices and even quantum logic gates. We can observe changes in exciton dephasing rate in TMDs under high magnetic fields and use four wave mixing spectroscopy to better understand and manipulate exciton dynamics. Using the MONSTR apparatus, we took FWM measurements of a monolayer MoSe_{2} sample, scanning from negative to positive delay signal to analyze the dephasing time of excitons. We applied magnetic fields up to 25T and altered the polarization scheme of the excitation pulses from crosscircular to cocircular to observe the dependence of exciton dephasing rate on these factors. The preliminary data suggests nonMarkovian behavior, which can be seen in the broadening of the FWM signal. This may be a result of increased biexciton formation, which we learned may be tuned using a magnetic field. In the future, the application of a magnetic field onto heterostructure TMDs may also provide interesting insights, particularly into the dynamics of interlayer excitons. 

C71.00037: The magnetic structure of a strongly correlated rareearth based intermetallic system Au_{2}PrIn._{.} Svetlana Doroshevich, Nami Uchida, Kalani Hettiarachchilage, Neel Haldolaarachchige The electronic structure of the rareearth based intermetallic system, Au_{2}PrIn, is studied using computational methods. The material, a member of a large family of Heusler compounds, was recently discovered, and only crystallographic data was reported. The never reported Lanthanum version (Au_{2}LaIn) was also studied for the comparability of nonmagnetic analogue. Both Au_{2}LaIn and Au_{2}PrIn show threedimensional metallic nature with large band dispersion at Fermi level in electronic structure. Au delectrons are dominated in the electronic band structure of La system, whereas rareearth felectrons are dominated in the electronic structure of Pr system. The study suggests that the magnetism develops as the forbital fills up from nonmagnetic Lacompound to magnetic Prcompound. The electronic band structure of Pr compound shows local magnetism with felectron bands near the Fermi level. Calculated magnetic moment is comparable with the expected magnetic moment of Pr. Calculated Curie temperatures are comparable with the stable magnetic structure predicted by spin polarized calculations. Detailed results of electronic and magnetic properties of Prsystem with the predicted magnetic structure will be presented. 

C71.00038: MCG modelling and eccentricity calculations for Pb+Pb and Au+Au collisions at various √s_{NN} Anya Wolterman Glauber models provide insight into the initial state of nuclear collisions by treating them in terms of the interactions of the constituent nucleons, in accordance with theories about the scattering of composite particles. These phenomenological techniques are commonly used to determine various geometric quantities associated with such femtoscopic manybody systems. The Glauber Monte Carlo approach uses a random impact parameter and measured nuclear densities to investigate quantifiable properties such as the particle multiplicity and the average geometric eccentricity for heavy ion collisions. The former involves the incorporation of a particle production model to calculate the total transverse energy, a measure of centrality. The latter delves into the eccentricity of different event classes, which can be used to characterize various collision shapes for measurements of elliptic flow of heavy mesons. The results of both applications are then compared with analyses of data from the CMS and STAR experiments. 

C71.00039: Utilizing Electronics to Extend the Life of Musical Instruments Rebecca Callaway, Mary Dye, Adam Schoene Musical instruments are often discarded when the cost of fixing an issue becomes an inconvenience. Millions of dollars worth of instruments are thrown away each year while communities around the country struggle with funding art and music programs. This causes music to become a privilege and for certain instruments to be only associated with certain socioeconomic classes. A new system needs to be designed where students and teachers can be exposed to musical instruments without having to worry about financial constraint. Instead of disposing of an expensive instrument and adding to landfills, mass produced electronic components can be used to extend its functionality as an educational tool. Affordable light sensors are used in place of the core sound producing material on the instrument. Software is combined with the light sensors in a manner to reproduce the sound it would make with original materials along with the ability to manually change the tone. Due to an electronic interface, performance can be easily recorded in notation software to keep track of progress and enhance the musicians understanding of music. 

C71.00040: Study on the Spontaneous Elemental Lysis of an Electrolyte due to the presence of a Static Magnetic Field from contact with a socalled Permanent Magnet Debosmita Pathak, Rajatava Mukhopadhyay This is a project to verify the results of a controversial experiment performed by Prof. Felix Ehrenhaft (1944). The absence of any constructive follow up research work for 74 years has motivated this work. 

C71.00041: Synthesis and physical properties study of polar magnet HoFeWO_{6} Christian Bucholz, Duy Pham, Ram C Rai, Chetan Dhital Polar oxides are important system to study due to their technologically relevant properties such as ferroelectricity, multiferroicity, piezoelectricity, magnetoelectricity. Recently, RFeWO_{6} (R=Dy, Y, Tb, Eu) type polar oxides were synthesized and typeII multiferroic property was reported [1]. We have extended this series and successfully synthesized HoFeWO_{6} in polar structure. We have also characterized this material using dielectric and magnetization measurements. We will present the synthesis method and the results from the dielectric, structural and magnetic measurements. 

C71.00042: The Development of FourWave Mixing Spectroscopy to Measure Vibrational Spectra in the LowFrequency Terahertz Range Benny Schundelmier, Laszlo Janos Ujj We report the progress of developing fourwave mixing spectroscopy to measure vibrational spectra in the lowfrequency terahertz range. The optical tabletop system, we have improved in the Laser Spectroscopy Lab at the University of West Florida is a multipurpose system [1], capable of executing a variety of spectroscopy methods such as e.g. Raman, Coherent Raman, and LaserInduced Breakdown spectroscopy. For this project, our focus is on Coherent Raman Spectroscopy, through threecolor twobeam broadband nonlinear frequency mixing. The threecolor nature of the fourwave mixing signal allows for an effective nonresonant signal suppression relative to the polarized and depolarized Raman bands. This type of nonlinear fourwave mixing has not been fully utilized for ultrafast coherent Raman microscopy. To demonstrate the precision and merit of our modified system, we present measured and processed spectra of liquid and crystalline samples and provide a characterization of the critical components that constitute our system. 

C71.00043: Thermal Analysis of Pr_{1x}Nd_{x}Os_{4}Sb_{12 }in Normal State Matthew Chazle Brown, YehChia Chang, PeiChun Ho, M Brian Maple, Tatsuya Yanagisawa At low temperatures, the filledskutterudite compounds PrOs_{4}Sb_{12} and NdOs_{4}Sb_{12} exhibit states of unconventional heavyfermion superconductivity (SC) and ferromagnetism (FM), respectively. Thus, we have interest in studying the doping system of Pr_{1x}Nd_{x}Os_{4}Sb_{12} in order to identify the competing mechanisms between the two states. Because the multiband superconductivity in this system may still be influenced by the electronphonon mechanism, the normal state properties may give us insight into the properties of conduction electrons and phonons. The molar specific heat of Pr_{1x}Nd_{x}Os_{4}Sb_{12 }is measured in the normal state 10K300K, and the thermodynamic parameters are extracted by incorporating Debye Temperature, Einstein Temperature, and the electronic specific heat coefficient, which provide information about the lattice stiffness, rattling effect, and electron correlation, respectively. Our findings convey that the Debye and Einstein temperatures have a V shaped x dependence that decreases towards central values of x, following the trend in transition temperature of low temperature ordered state. 

C71.00044: Ferromagnetic Resonance of All Oxide Core / Shell Nanoparticle Variants N. Schulz, Corisa Kons, J. Shoup, J. Robles, ManhHuong Phan, Hariharan Srikanth, Dario Arena Coreshell magnetic nanoparticles (MNPs) are being considered for various applications in spintronics as well as in the biomedical field. Ferromagnetic Resonance (FMR) is a widelyused technique for determining magnetic properties such as bulk magnetization and anisotropy, gyromagnetic ratio / gfactor, and damping. Broadband FMR using a coplanar waveguide (CPW) is wellsuited for examining properties of thin film samples, but MNPs present some challenges. MNPs can have a wide distribution of sizes and crystalline orientation. Also, at room temperature MNPs are generally superparamagnetic, where the magnetic orientation is unstable against thermal fluctuations. This research sought to adapt the standard CPWFMR methods for thin films to characterize the resonant responses of MNPs, starting with commercially available magnetite (Fe_{3}O_{4}) MNPs and progressing to more complex Fe_{3}O_{4}/CoFe_{2}O_{4} coreshell nanoparticle variants. Protocols were developed for mounting the different MNPs onto substrates suitable for CPWFMR. The temperature and frequencydependent resonant response of the MNPs was explored. The determination of specific sample properties extracted from the CPWFMR methods will be discussed. 

C71.00045: Generation Optical Beating between Hyperfine levels in the Decay of Rb atoms Excited by Different Pulse Shapes. Olivia Chierchio, Charanpreet Singh, Zafir Momin, James P St. John, Matthew Wright We are investigating quantum interference in the atomic decay signal in a dilute thermal atomic gas with an intense pulsed laser beam. A short pulse of laser light (~ 3 ns) is used to drive atoms from the ground state to an excited state hyperfine manifold of levels. We are exploring how quantum beating and other excitation properties depend on the shape of the driving frequency (e.g., cw, chirped, whitenoise, etc). 

C71.00046: Analysis of Time Evolution Algorithms to be Utilized in Modeling Classical and Quantum Mechanical Systems Katherine Hudek, L Ramdas RamMohan Time evolution in classical and quantum mechanical systems has been the focus of research because the behavior of physical systems with time are determined by their initial conditions. Calculation methods for the system values as it changes throughout time have to be very accurate in order to have predictions that we can rely on. This is the challenge of time evolution and its modeling. 

C71.00047: Verifying 2D device potentials and conduction with Kelvin Probe Force Microscopy Joel ToledoUrena, Joseph Murphy, Rebekah Smith, Joseph Simpson, Jennifer T Heath In a 2D field effect transistor (FET), the electrical properties of the channel are modulated using a gate voltage. The electrostatic doping of the channel and the contact resistance of the interacting layers both contribute to the overall device conductivity, which plateaus above a certain gate voltage. Other factors, such as surface cleanliness and microscopic details of the films also influence the conductivity as can be deduced from variations between multiple devices. In this study, we explore the ability of Kelvin probe force microscopy (KPFM) to separate out the different factors influencing overall device conductivity. By applying a potential bias to a simple device, we build confidence in the linear response and reproducibility of the KPFM technique. We then directly visualize the uniformity of the surfaces, the potential barriers between layers, and the characteristics of the WSe_{2} film as a function of the applied voltage. These data deepen our understanding of device potentials and conduction in 2D FETs. 

C71.00048: Detecting topological superconductivity by using a dcSQUID Benjamin Hawn, Joseph Pakizer, Alex Matos Abiague We theoretically investigate the current and phase response of a dcSQUID composed of two Josephson junctions (JJs) in parallel. The JJs are exposed to an inplane magnetic field and their chemical potential and Rashba spinorbit coupling strength are tuned by top gates acting separately on each of the junctions. By tuning the system parameters, each JJ can individually be driven from the trivial to the topological phase and vice versa. We investigate the 3 possible dcSQUID configurations: the two junctions are topological, one junction is trivial and the other topological, and the two junctions are trivial. We perform theoretical simulations of the phase difference and critical current of the dcSQUID for the 3 different configurations, and by comparing them we identify the signatures of the topological superconducting phase and its dependence on junction transparency, magnetic field, and spinorbit coupling. 

C71.00049: Water and Carbon Dioxide in Hydrated Hyperbranched Polyethylenimine Membrane Using Molecular Dynamics Simulation and Density Functional Theory Kyung Il Kim, Robin Lawler, Seung Soon Jang Since excessive use of fossil fuels is releasing large amounts of CO_{2} and exacerbating global warming, developing efficient materials to capture CO_{2} is crucial. In this study, we investigate the hydrated hyperbranched polyethylenimine (HBPEI) membrane in the presence/absence of water and carbon dioxide using molecular dynamics (MD) simulation to characterize their distribution and reaction mechanism in the HBPEI membrane. For this, we prepare a model HBPEI molecule and construct a condensed HBPEI phase in the amorphous phase with various concentration of water and carbon dioxide molecules. Largescale Atomic/Molecular Massively Parallel Simulator (LAMMPS) package is used in our MD simulations to establish the equilibrium state of HBPEI membranes. Through our MD simulations, we obtain samples of the local structure of water/carbon dioxide nearby amine groups in HBPEI membranes and scrutinize a possible molecular mechanism and corresponding energy barrier for carbon dioxide capturing, via density functional theory (DFT) approach. 

C71.00050: An evaluation of methods for measuring thermomagnetic transport properties of bulk and thin film materials Andrew Jarymowycz, Jason Pruitt, Kyle Thomson, Austin Tinkess, Matthew Beekman In the “method of four coefficients,” experimental data for electrical conductivity, Seebeck, Hall, and Nernst coefficients are fit to models based on Boltzmann transport theory to estimate quantities such as the carrier effective mass, concentration, mobility, and scattering exponent. This powerful method provides experimental information about the electronic structure and charge carrier scattering mechanisms in solids, and has been used to understand enhanced performance in some thermoelectric materials. Nevertheless, there is relatively little literature available regarding descriptions of experimental apparatuses and methods of measurement of all four coefficients on a single sample in a single measurement cycle. We recently constructed a custom system for measurement of thermomagnetic properties from 8 K to 400 K. Here we report on a study of different approaches for experimentally measuring these four coefficients on both bulk and thin films samples. For example, we have investigated the effect of mounting the sample in a flat vs. vertical geometry, which can be important for adiabatic vs. isothermal Nernst measurements. Our results provide useful guidance for constructing such apparatuses to measure the thermomagnetic properties used in the method of four coefficients. 

C71.00051: Analyzing Challenging Scientific Thoughts in a Christian Academic Setting Mason Pohlman Throughout a significant portion of history and within modern culture, the fields of science and religion appear to be competing for the same holds in a person’s belief system. Universities are where academics and the sciences are the prevailing held truth, while in churches, the Bible reigns as supreme authority. However, in a Christian academic setting, the predominate school of thought in belief systems might turn into a little more of a melting pot. By analyzing gathered personal data (via surveys and interviews), one can begin to piece together the predominate thoughts on the apparent conflict between religion and science at such a setting. Institutions such as this, while always diverse in thought, can present a cohesion between the two seemingly opposed parties in a way where neither side loses ground culturally. Data gathered on personal religious experience, beliefs and experiences gathered around evolution, creationism, the Big Bang, and other issues that fall from that have been collected to present an image of how science and religion might be in understanding at a Christian house of higher education. 

C71.00052: Electronic and Structural Properties of Ybbased Materials Britney Hopgood, Chinedu Ekuma We have investigated the electronic, structural, and optical spectroscopy of YbT_{2}Zn_{20}based (T = Co, Rh, and Ir) 1220 compounds using firstprinciples calculations that account for the strong onsitefelectron Coulomb interactions. We observed the strong hybridization and screening of the flevels by the itinerant conduction electrons that led to massive electron behavior with an unenhanced electronic Sommerfeld coefficient of over ~600 mJ mol^{1} K^{2}. The optical spectroscopy exhibits renormalized Drude response, a partial enhancement of the dynamical conductivity below ~1.0 eV, the emergence of the midinfrared peak structures at ~0.46 eV, and low photonenergy dynamical effective mass and scattering rate with nontrivial energydependent scattering resonances from free carriers. Surprisingly, both the electronic and optical spectroscopy of YbT_{2}Zn_{20} are distinctly different from the rest of the studied materials, with characteristic features that support its closeness to quantum criticality. 

C71.00053: 395 GHz Sample Holder Waveguide for Dynamic Nuclear Polarization Kirsty Scott, Thierry Dubroca A major issue in nuclear magnetic resonance (NMR) is the low sensitivity which can be achieved as a result of the small magnetic moment in nuclei. At the MagLab, we exploit dynamic nuclear polarization (DNP), which increases NMR sensitivity through a process in which electron spins transfer their larger polarization to the nuclei of interest, to yield larger DNP signals at 14 T. For DNP experiments, our spectrometer uses a sample holder which doubles as a waveguide for the microwave used to saturate the electrons in the sample under study. The lack of axial symmetry in this sample holder limits our range of experiments. 

C71.00054: Effect of Postdeposition Thermal Treatment on the Structural and Electrical Properties of Oxygen Deficient Perovskite Metal Oxide Thin Films Benjamin Moore, Skyler King, Francis F Walz, Anton D Wiggins, John Leventis, Charles J Ay, Grace Yong, David Schaefer, Gary Pennington, Rajeswari Kolagani Thin films of perovskite metal oxides such as SrTiO3 (STO), La_{0.67}Ca _{0.33}MnO_{3} (LCMO) and CaMnO3 (CMO) exhibit many interesting electronic properties that are useful for technological applications. These properties are highly sensitive to the oxygen stoichiometry in the thin films, which can be varied by subjecting the thin films to heat treatment (annealing) after the film is deposited. We will discuss the results of our experiments to study changes in the lattice constants and electrical resistivity induced by postdeposition annealing in various gas ambients and in vacuum. We will also present the effects of annealing in the presence of a fluorinecontaining polymer with the goal of incorporating fluorine in the film crystal structure. Thin films in this study are grown using pulsed laser deposition, lattice constants are determined using 4circle xray diffraction and resistivity is measured using a 4probe VanDerpauw technique. 

C71.00055: Unsupervised Machine Learning for Rare Signal Detection in CMS Detector Data Luc Le Pottier, Annapaola DeCosa We present here a method for identifying highp_{t} beyond the Standard Model (BSM) signals, with no dependence on the expected physics signatures of these models. We do this by constraining our detector data to the expected signal region of a given model and training a deep neural autoencoder to 'recognize' jets belonging to the Standard Model (SM) background data. In this way, our models learn the background signature of SM jets in our signal region. We then evaluate this model on a mixture of SM and BSM jets, flagging jets with a high autoencoder reconstruction error as 'anomalous' or signal jets. This method of searching independently of any physics model is especially useful when the BSM model in question involves particles of unknown mass, branching fraction, etc. This is especially relevant in Dark Matter searches, such as the search for SemiVisible jets in missingE_{T} events at the LHC. In these cases, our models are capable of flagging a range of BSM models with different parameters within our signal region, as opposed to a supervised model (such as a Boosted Decision Tree) which is only able to flag the exact signal it was trained on. We show that this technique is a promising method of identifying arbitrary BSM signals to high precision in LHC data. 

C71.00056: Monte Carlo simulation on ferromagnetic monolayer of honeycomb CrI_{3} Hao Li, JaeHo Chung Since the discoveries of robust twodimensional ferromagnetism in CrI_{3} [1] and Cr_{2}Ge_{2}Te_{6} [2], many research interests have focused on thermal stabilities of magnetism on van der Waals monolayers. In this work, we investigated the thermal evolutions of classical spins on 2D ferromagnetic honeycomb monolayers during simulated cooling and/or annealing by using the Monte Carlo method. Using the Heisenberg Hamiltonian with parameters proposed for CrI_{3} [3], we closely reproduce the experimentally observed temperature and inplane magnetic fielddependences of the magnetization including the size of the Curie temperature [1]. We also find that in zerofield cooling CrI_{3} monolayers exhibit multiple domains with high densities of domain walls. We will present how the domains behave as the temperature or magnetic field is changed. 

C71.00057: Models and Simulations of Electric FieldBiased Nanoparticle SelfAssembly Matthew Withers, Elise Baker, Benjamin Wood Zeman, Nolan Zunk, Cory Morris, Dan Mazilu, Irina Mazilu We design, model, and simulate an experiment to study the effect of electric bias on particlecoverage densities produced during ionic nanoparticle selfassembly. The experiment involves the application of a uniform external electric field parallel to a glass substrate during the 

C71.00058: Correlating MultiphotonAbsorptionInduced Luminescence (MAIL) with Morphology in NobleMetal Nanostructures Anna Grafov, Xiaoying Lin, Farah Dawood, John T Fourkas The optical properties of nanostructured noble metals differ drastically from those of their bulk counterparts due to surface plasmon (SP) resonance. When incident light couples with the SPs of a noblemetal nanoparticle, it gives rise to strong, localized electromagnetic field enhancement. In particular, surfaces with high curvature experience especially strong field enhancement. Silver and gold SP absorption cross sections lie in the visible region, which make nanostructures of these metals ideal for studying optical phenomena. Multiphotonabsorptioninduced luminescence (MAIL) is a nonlinear optical phenomenon that involves ultrafast pulses of light impingent on a nanostructured surface. The SP field enhancement allows for more efficient multiphoton absorption, and highlyefficient, broadband luminescence over the visible spectrum is produced as a result. We examine how the morphologies of noblemetal nanostructures correlate with their MAIL signals. Specifically, we focus on silver nanodendrites, synthesized from galvanic displacement reactions, and gold nanorings and nanotriangles, grown through colloidal synthesis. The absorption order, intensities, and spatial distribution of MAIL signals are examined for different morphologies. 

C71.00059: Characterizing the Mechanical Properties of 3D Printed Structures for Growth Plate Tissue Engineering Rachel Hecht, A. Camila Uzcatequi, Victor Crespo Cuevas, Robert R. McLeod Stem cell differentiation is highly sensitive to the biochemical and mechanical environment. A major concern in tissue engineering is the need of a robust technique for producing structures with the precise amount of rigidity to guide stem cell differentiation. Damaged cartilage within the physis does not regenerate easily and can lead asymmetric growth arrest, making it an ideal model application. The physis has three distinct zones where cells evolve differently depending on the environmental conditions. Previous in vivo rabbit studies indicate that the mechanical properties of the 3D printed structures implanted in this area have an effect on stem cell differentiation in the area. In this work we use a solvent solution consisting of a multifunctional acrylatebased resin and ethanol to control the overall modulus of the structure. 3D printed pillar structures of varying solvent concentrations and backfills (air and a poly(ethylene glycol) diacrylate based hydrogel ) were put through compression testing and we found that there was an apparent reduction in the modulus of higher concentrations of the solvent solution of over 30 percent. This work allows us to control the modulus of 3D printed structures, which can be applied to future stem cell differentiation studies. 

C71.00060: The Effect of Short Range Attractions on Sequence Defined Polyelectrolyte Coacervation Natalia Markiewicz, Tyler Lytle, Charles Sing Complex coacervation is the liquidliquid phase separation of polyelectrolytes in aqueous salt solution into a polymerdense phase, the coacervate, and a polymerdilute phase, the supernatant. Previous work using Monte Carlo simulations demonstrated that changing the sequence of charged and neutral monomers on polyelectrolytes while keeping the charge fraction constant alters the extent of phase separation. However, previous data does not account for the hydrophobicity of different neutral monomers. To understand the coacervation of polymers with various chemical structures, van der Waals interactions at various strengths are included in Monte Carlo simulations to show hydrophobic effects in the system. Comparisons are made to existing Monte Carlo simulations and experimental data. Understanding these patterning effects will enhance the knowledge of biomacromolecule phase separation, as well as expand the understanding of sequencedependent polymer physics. 

C71.00061: AllDielectric Nanophotonics Research Involving Undergraduates at Illinois State University Brighton Coe, Daniel Eggena, Hiroshi Sugimoto, Mahua Biswas, Minoru Fujii, Uttam Manna Resonant excitation and manipulation of highindex dielectric nanostructures (such as Silicon, Germanium) provide great opportunities for engineering novel optical phenomena and applications. Here, we report selective excitation and enhancement of multipolar resonances, and nonradiating anapoles in silicon nanospheres using cylindrical vector beams (CVBs). Our approach can be used as a spectroscopy tool to enhance and identify multipolar resonances as well as a straightforward alternate route to excite electrodynamic anapoles at the optical frequencies. 

C71.00062: Silica Polypeptide Composite Janus Particles Sean Ronayne, Alyssa Blake, Elsa Samantaray, Jamie wooding, Mark Lasego, Paul Russo Janus particles are interesting materials due to their inherent dual face properties. The ability to be able to have different functionalization and properties on a single particle allows these materials to be used for drug delivery and interfacial chemistry. Silica polypeptide composite Janus particles are unique because they are stimuliresponsive particles containing an organic polypeptide shell with an inorganic colloidal silica core, half of which is coated in chromium. The responsive nature comes from the polypeptide shell consisting of the homopolypeptide, poly (εcarbobenzyloxyLlysine) (PCBL), which is known to exhibit a reversible coilhelix transition when dissolved in mcresol. The silica core particle can be removed from the particle via etching to retain a hollow polypeptide vesicle, potentially with the chromium still bound to part of the vesicle. These can be used to study the conformational transition of the polypeptides while being structured but without being tethered to a solid surface. This will help to better understand the polypeptides role as a drug delivery vesicle. 

C71.00063: Arbitrary SuperResolution Patterns Formed in Quantum Dots Thomas Danza, Richard O Mouradian, Mateo Murillo, Sean James Bentley


C71.00064: Using Depolarized Dynamic Light Scattering to Characterize Microgel Dependence on Synthesis Temperature Andrew Scherer, Kiril Streletzky Microgels formed by crosslinking polysaccharide polymer chains exhibit a thermally reversible volume phase transition due to the amphiphilic properties of the parent polymer. Specifically, the microgels deswell above a volume phase transition temperature, T_{v}. Microgel dynamics above and below T_{v} has been studied extensively by dynamic light scattering (DLS) before. Here, the structure and dynamics of microgels synthesized at various temperatures are investigated through the use of depolarized dynamic light scattering (DDLS). The technique has previously been used in our lab to examine solely geometric anisotropies in nonspherical particles. It has also been used in the literature to study shape fluctuations in microgels that have a hard, polystyrene core and a soft, polymer shell. This research project looks into a possibility that the observed DDLS signal above T_{v}, for microgels synthesized at various temperatures, arises from microgel shape fluctuations. 

C71.00065: Neutron Spectrum Unfolding with Deuterated Liquid Scintillator Detectors Fabio Rivero, Jesus F Perello, Sergio J AlmarazCalderon The detection of neutrons from nuclear reactions is becoming increasingly important in nuclear physics experiments. Neutron measurements are needed for understanding reactions that drive stellar explosions and provide insight into the behavior of exotic nuclei. Traditionally, neutron energies are obtained by the timeofflight (ToF) method which consists in measuring the time that neutrons take to travel from the target to the detector. The quality of the measurements is limited by the distance traveled, the solid angle spanned by the detector array, and a background of gammarays and scattered neutrons. Pulseshapediscrimination (PSD) allows one to distinguish, in certain detectors, neutron and gammaray interactions due to their decay times. A promising method in neutron research involves the use of deuterated liquid scintillators as neutron detectors where a unique correlation in the pulseheight (PH) information can also be extracted. In this work a method of unfolding neutron spectra will be presented. A response matrix is created from deuterated liquid scintillator detectors by combining PSD and PH data to obtain neutron energies alongside ToF. This method will enhance neutron studies relevant for nuclear structure and nuclear astrophysics research. 

C71.00066: GoldAluminum Thin Films as an Alternative to Pure Metals for Plasmon Resonance Sensors Abdul Qadeer Rehan, Robert Malcolm Kent, Mariama Rebello Sousa Dias Noble metal alloys have been widely investigated as an alternative to pure metals for improving the optical response of optoelectronic devices in the visible range of the electromagnetic spectrum. However, their use is hardly extended to the ultraviolet (UV) range. As an alternative, aluminum (Al)based alloys could expand the functionality of photonic devices into the UV range. In this work, we fabricate and measure the dielectric constant of binary mixtures of gold (Au) and Al thin films. The films were deposited on a glass substrate via the cosputtering method. The dielectric functions were measured using spectroscopic ellipsometry. We investigated how the optical response of the samples changed under a wide range of temperatures, from 25°C to 200°C. Also, we performed AFM, SEM, XRD, and EDS measurements. We demonstrate that, in all our cases, a bimetallic material outperforms their pure metal counterparts in the nearIR range after the temperature treatment, e.g., Al0.51Au0.49 shows an increased quality factor of its surface plasmon polariton (QSPP) than pure Au and Al. To verify our calculations, we measured the SPP of pristine and temperature treated samples. 

C71.00067: Water Wheel Generator Brigid Long The world continues to move toward ecofriendly renewable energy by creating new, more advanced technologies. Solar panels, wind turbines, and dams are some of our biggest contributors. This project takes a second look at the potential of bringing the vertical water wheel back into the limelight. Historically water mills have been crucial in the progress and growth of civilization by being a major source of strength and power. Combining this power with a continuously recycled water flow has the potential to create a constant source of renewable energy. Using the principles of water wheel designs that have been perfected over centuries and securing a small generator creates a viable configuration for a tabletop water powered generator. The goal is to create an enclosed system where a water wheel powers its own pump for recycling water flow and still outputs enough wattage to be used to charge batteries. This prototype has gone through rapid prototyping using 3D printed wheel designs for the optimization of electrical output. On a small scale this design can be a tabletop charger however, on a larger scale, this design could power homes and office buildings without the hazards of daming. 

C71.00068: Reaction Kinetics and Mechanical Properties of Reversible Epoxies by DielsAlder reaction nicole penners, Youngmin Lee <p>Epoxies are an important class of thermosetting polymers for many longterm applications such as adhesives, structural materials, and coatings. Epoxies have durable and robust mechanical properties; but, they are difficult to remove, recycle and rework. Epoxies capable of reversible polymerization could solve these problems. In this experiment, reversible epoxies were synthesized by introducing the DielsAlder reaction groups to epoxy monomers. 1,1'(Methylenedi4,1phenylene) bismaleimide and furfuryl glycidyl ether were reacted to form a DielsAlder cycloadduct. This cycloadduct was confirmed using Fourier TransformInfrared (FTIR) Spectrometry. The forward and reverse DielsAlder reaction was monitored by FTIR measurements at 90 ^{o}C and 110 ^{o}C as a function of exposure time. IR absorption peaks relevant to the reverse DielsAlder reaction grew due to longer exposure time at 90 ^{o}C and 110 ^{o}C. The equilibrium shift was observed toward the reverse reaction dominant side at higher temperature by comparison of FTIR spectra at 90 ^{o}C and 110 ^{o}C. Mechanical properties of the reversible epoxies was examined to confirm two states of reversible epoxies: a durable network at lower temperature and soft segments at higher temperature.</p> 

C71.00069: Hyperentangled Bellstates analysis of twophoton 2ndegreeoffreedom system Chunzhen Li It is known that it is impossible to unambiguously distinguish all the Bell states in one system using only linear optics even if you also use hyperentanglement. However, we can find out how many Bell states can be unambiguously distinguished with a given n in twophoton 2ndegreeoffreedom hyperentangled system. This work, based on the criterion of Peter van Loock and Norbert Lutkenhaus, uses the symmetric matrix to express Bell states and the number of distinguished Bell states can be obtained by the rank of a matrix made with all the Bell states. The results show that with the increase of n, the number of distinguished Bell states increases exponentially by 2^{n+1}1, while the efficiency of discrimination decreases exponentially by 1/2^{n1}. This work lays a foundation for Bellstate analysis of threephoton system. 

C71.00070: Electronic Stucture of Negative Trions in Semiconducting Quantum Dots Jayden Leonard, Que Huong Nguyen


C71.00071: Floquet Engineering in 1D NonHermitian Model Houchen Li Topological properties of nonhermitian and periodically driven (floquet) systems have attacted great attention in recent years. Here, I find we can introduce robust topological edge state in 1D nonhermitian timeperiodic system while its static counterpart is trivial. Also when we adjust the frequency of the outer driving within the regime around the bandwidth Δ, topological phase transition of the system has a similar behavior with the Hermitian counterpart[1]. This will help us understand nonhermitian and floquet systems better. 

C71.00072: LowPressure Plasma Device for Activation Bonding Polydimethylsiloxane(PDMS) to Glass Jacob Carney, Krista McBride Surface activation of PDMS through plasma treatment is a common technique used in the fabrication of microfluidic chips for a strong bond between PDMS and glass. Plasma treatment can be done in an open lab or lowpressure environment, in which commonly produces more activated stronger bonds. The activation levels of plasma treatment of PDMS and glass can be measured using atomic force microscopy. A lowpressure plasma bonder is being built and tested in order to produce stronger microfluidic devices. The configuration and experimentation of the selfbuilt lowpressure plasma generator will be presented. 

C71.00073: Electrocolonography: NonInvasive detecton of colonic cyclic motor activity from multielectrode body surface recordings Laura Bruce, Jon Erickson, Andrew Taylor, Jack Richman, Connor Higgins, Beth Reed, Riwaj Shrestha, Jack Robey, Utkrist Thapa Approximately 20% of Americans suffer from colonic motility disorders, including slow transit constipation (STC) and irritable bowel syndrome (IBS), with significant physical and social morbidity. Accurate clinical diagnosis is often challenging due to the nonspecificity of symptoms. In addition, the only direct assessment tool available in current clinical practice is colonic manometry, which involves placing a small, flexible tube, or catheter, through the rectum and into the colon. There is a substantial need in both colon research and clinical practice for an accurate, noninvasive method to analyze colon motor activity. This work validates a novel noninvasive method to identify periods of cyclic motor activity in the colon using multichannel skinsurface electrical recordings on the lower abdominal region, termed electrocolonography (EColG). We also explore several spatial filtering techniques to identify wave propogation of the colon. 

C71.00074: Exploring the Memory Capacity of Embedded Synfire Chains Sarah Greberman, Yevhen Tupikov, Dezhe Jin Memory is a longstudied property of neural systems that is not well understood yet essential for the success of any animal. The synfire chain is a popular sequence generating model which has been hypothesized to represent a building block for neural computation and memory. Our research was conducted to explore what affects the storage capacity of memory networks composed of embedded synfire chains. Using computational modeling, we compared the memory capacity of two neuron models – Leaky IntegrateandFire (LIF) and Izhikevich – and systematically varied factors that showed to affect each network. In both cases, we used a simplified model of global inhibition to control runaway excitation. Our studies showed that the memory capacity for networks consisting of LIF neurons depends strongly on the inhibition, excitation, and width of the chains. The observed memory capacity was low and insufficient for practical applications. The memory capacity for networks consisting of Izhikevich neurons was considerably larger. More research needs to be done on this. Future directions would also explore more targeted models for inhibition in hope for achieving larger capacity for memory networks. 

C71.00075: Enhancement of Nonlinear Optical and Piezoelectric Properties in Ferroelectrics from SymmetryBreaking Strains Bailey Nebgen, Rui Zu, William Nunn, Bharat Jalan, Venkatraman Gopalan In the pursuit of leadfree piezoelectrics, recent studies have used temperature, pressure, applied voltage, and other methods to enhance piezoelectric properties in ferroelectrics. Here, we investigate changes in symmetry, polarization, and domain structure near phase boundaries in BaTiO3 crystals and BaTiO3xBaSnO3 thin films in order to understand how property enhancement depends on external stimuli and replicate the property enhancements in versatile thin films. We use second harmonic generation (SHG) polarimetry to detect changes in point group symmetry and polarization direction, supplemented by scanning SHG microscopy, which reveals the domain structure and allows polarimetry of specific domains. We observe lowersymmetry monoclinic phases with SHG and piezoelectric property enhancements of up to 4 times near temperature phase boundaries and with applied voltage in BaTiO3 crystals. In addition, we observe similar symmetry lowering near a compositional phase boundary of BaTiO3xBaSnO3 thin films, indicating the potential for similar property enhancements in the thin film system which is more easily integrable into a variety of devices. 

C71.00076: Compaction and Creep in a Photoelastic Granular System Edna Olvera, Nakul Deshpande, Cacey Stevens Bester, Doug Jerolmack Creep is the subsurface, slow movement and deformation of constituents in a granular packing, such as sand or sediments, due to the applied stress and disordered nature of its grainscale interactions. The phenomenon of creep in dense granular systems is relatively understudied, leaving many open questions. We explored creep through experiments in which we observed the influence of a controlled disturbance on rearrangements in a granular packing. Our granular system consists of disks that are made from a birefringent material; this allows us to use image acquisition to observe both the movement of the grains and the changing stress distribution within the system. In the experiment, we deliver disturbances via taps of a pendulum to one side of the chamber that contains the granular packing. The tapping strength is measured using an accelerometer. We tilt the chamber to varying slopes to observe changes in system response as we approach the critical slope for more rapid granular flow. Using image analysis, we examine grain rearrangements, changes in packing density, and stress redistribution as the grains creep due to these disturbances. 

C71.00077: Influence of Spincoating Speed and Mixing Ratio on PolymerFullerene Films Sebastian Valbuena, Charity Diamonon, Cameron M Prosser, Prof Weining Wang Due to increasing environmental concerns and depletion of nonrenewable resources, different forms of renewable energy must be studied. Organic solar cells are a very popular and promising form of renewable energy; however, they are still relatively new and not as well studied in comparison to traditional silicon solar cells. Thus, it is important to gain more knowledge on how those organic solar cells could be enhanced in different areas. Among the organic solar cells (OSC), OSC based on polymerfullerene bulk heterojunctions have attracted much attention due to their low cost and easy processing conditions. The most common polymerfullerene bulk heterojunction is poly(3hexylthiophene) (P3HT) and [6,6]phenylC61 butyric acid methyl ester (PCBM). 

C71.00078: The Durability of a Chiral Auxetic Structure Anna Repesh, Xin Du


C71.00079: Thermodynamic and Magnetic Properties of the System Ca_{3}Co_{2x}Zn_{x}O_{6} Alexander Mantilla, Jani Jesenovec, Benjamin White The crystal structure of Ca_{3}Co_{2}O_{6} is built from chains of Co^{3+} ions that are separated by Ca ions. Magnetic moments associated with lowspin Co ions are located on trigonal prismatic sites within the spin chains. Ferromagnetic intrachain interactions are an order of magnitude stronger than antiferromagnetic interchain interactions, leading to a quasionedimensional magnetic structure. In an effort to study its magnetic state, we substituted Zn^{2+} for Co^{3+} ions. Zinc ions occupy the trigonal prismatic (magnetic) sites and charge balance causes low spin Co^{3+} ions occupying octrahedral sites to become lowspin Co^{4+}. Thus, Zn substitution dilutes moments on trigonal prismatic sites and induces them on octahedral sites. Samples of Ca_{3}Co_{2x}Zn_{x}O_{6} were synthesized via solid state reaction and phase purity was evaluated via xray diffraction. Xray diffraction elucidated a solubility limit near x = 0.1. Heat capacity and magnetization were measured as a function of temperature and were used to construct a T vs. x phase diagram for Ca_{3}Co_{2x}Zn_{x}O_{6}. In this poster, this phase diagram will be compared to the previously reported phase diagrams for Ca_{3}Co_{2x}R_{x}O_{6} with R = Cu, Cr, Fe, Mn, Sc, and Ho. 

C71.00080: Image Analysis and Model of Cytoskeletal Filament Density of C17.2 Cells Benjamin Horine, Sabrina Jedlicka, Swetha Chandrasekar, Massooma Pirbhai SingleWalled Carbon Nanotubes (SWCNTs) have great potential in the biomedical field as a way to deliver materials into the body. However, the longterm effects on the body are unknown, especially in regards to the cytoskeletal filaments. Many cellular functions such as differentiation, cell shape, and motility rely on the aid of filaments, such as actin and nestin. Recent studies have demonstrated that internal and external stimuli can affect these filaments thus affecting cellular behavior. In this project, neural stem cells, specifically C17.2 cells were used and the distribution of the cytoskeletal filaments were modeled. A data set was created through Filament Sensor, a program created by Benjamin Eltzner, and ImageJ, to quantitatively process and enhance images. This poster will look into the distribution of actin and nestin throughout the cell. Future work will look at how SWCNTs affect the distribution of these filaments. 

C71.00081: Photoreduction was used to reduce the oxygen content in Graphene Oxide and correlated to Young’s modulus measurements Alem Teklu, Cameron Green, George Riser, Narayanan Kuthirummal


C71.00082: RF Antenna for Generation of SpinDependent Force on Cold Lithium Atoms Jianyi Chen, Ariel T Sommer This study aims to design a small radiofrequency (RF) antenna that can generate magnetic fields with magnitude of 1 Gauss. This RF antenna is useful because the generated fields can magnify the hyperfine state of lithium atoms which are used to study the quantum atomic gas at low temperature. However, the function of the RF antenna is restricted when the diameter of the antenna is constrained in less than 1 inch. This restriction is the result of a high energy loss caused by signal reflection in the circuits if the antenna is directly connected with the power supply. In order to reduce the loss, an impedance matching configuration should be introduced between the antenna and the power supply. At the end of the experiment, a small RF antenna with impedance matching configuration that can generate a magnetic field with desired frequency and amplitude is designed. 

C71.00083: Investigation of a LCoSSLM and Progressively More Difficult Applications of the SLM Including Optical Trapping Kade Tatkenhorst


C71.00084: Achieving Flat Gold Surfaces for the Organization of Organic Molecules Jacob Martin, Jessica Bickel Organic electronics are interesting for use in electronic devices but suffer in competition with inorganics due to their lower conductivity. Crystallizing organic semiconductors can increase their conductivities and a possible crystallization method is selfassembly driven by the topography and chemistry of an atomic surface reconstruction. This work aims to develop an atomically smooth Au(111) surface, which has a herring bone reconstruction. Many methods are known for samples in UHV, however these methods do not work in atmosphere or a glove box, such as is used in our lab. This work expands upon that of Maver et al. using torch annealing, which allows the atoms to rearrange into a lower energy state. We anneal the sample at 710±10°C for two minutes, and then three minutes at 410±10°C. This yields larger and flatter terraces compared to the unannealed material. The unannealed gold had mounds with no flat areas and a max depth of 7.6 nm. The annealed Au(111) had flat terraces, 1330 nm in size, with step heights in the order of .235 nm, which matches the interplanar spacing for Au(111). In the future, we will optimize this process to achieve large terraces by adjusting the temperatures and times used. 

C71.00085: Immunofluorescent biomarkers for distinguishing cell phenotypes in zebrafish somitogenesis and autonomous cellular oscillators. Yiyang Chen, Qiong Yang During zebrafish embryogenesis, coordinated genetic oscillations occur in a population of cells in the posteriormost tissues of the body axis, the tailbud and presomitic mesoderm (PSM), which will subdivide the embryonic body into morphological segments, called somites. It has been proved previously that single cells dispersed from tailbud will oscillate automatically. However, it remains unclear that which phenotype of the cells will present as autonomous oscillators. Tdomain transcription factors Ntla and Tbx16 will both express in the period of somitogenesis but in different regions. Immunofluorescence experiments for both genes demonstrated the distribution of cells in different phenotypes in zebrafish embryo during somitogenesis. Comparison of immunofluorescence results for 5somite stage embryos and highsomite stage embryos showed the change of PSM region. Combined with results for singlecell oscillation and statistical analysis, immunofluorescence for cell dispersals was able to tell the phenotypes of the oscillating cells. 

C71.00086: Stabilization of Francium Materials Using Cluster Compounds David Nunn, Ajit Hira, Edwardine Fernandez, Arrick Gonzales, Tino Pacheco, Alicia Fresquez, Mario Valerio We present a Quantum Mechanical study of cluster compounds Fr_{l }X_{m}Y_{n} and Ra_{l }X_{m}Y_{n} (X, Y = other; 0 =< l, m, n =< 10). Halflife λ of the most stable isotope of francium (^{223}Fr) is 22 minutes, and only 20–30 g of the element exists naturally at any given time. The melting point, the boiling point, and density of Fr are uncertain. Isotopes of radium are radioactive, but the most stable isotope ^{226}Ra has a halflife of 1600 yr. The stabilization of radium is known to have been experimentally achieved, using a solution in which an effluent and a metal chloride are mixed, then the previously obtained mixture reacted with a sulfate ion, to obtain effluent containing stabilized radium. The chloride can be a barium, strontium or lead chloride. We are looking to see if there are similar trends, in properties, for francium. So far, we have achieved a factor of 2.7 stabilization for some of the francium cluster compounds, compared to bare Fr in our calculations. There is the possibility of application of a stabilized Fr material as a catalyst promoter, or a remover of oxygen from vacuum tubes and light bulbs, or in atomic clocks, or in petroleum exploration, analogous to the practical uses of Cs. 

C71.00087: Arduinos and the XRay Diffractometer Mia Manzer, Kelley D Sullivan For Ithaca College's Senior Project, it is required that a student develop an idea for a project, as well as the budget, goals, proposal, and design of the project itself. This project discussed in this presentation is developing a connection between an Arduino and the XRay Diffractometer owned by Ithaca College. The goal is to have the diffractometer and Arduino communicate easily and allow for data to be taken during the experiment easily. We wanted to make sure that students would be able to take, as well as save, data in the simplest way possible. 

C71.00088: Assessing iOLabbased Laboratories in Online Instruction Emma Koller, Louis Leblond We implement an online introductory mechanical physics laboratory course that features the Interactive Online Lab (iOLab) device and a class structure that encourages student engagement and collaboration. The students in the online class achieved a learning gain of g = 0.55 on the FCI. The end of class survey showed that the students overwhelmingly (93%) valued the lab portion of the course. However, we can only infer their mastery of the lab learning objectives from lab related questions on exams and lab reports. We present an ongoing study that seeks to understand student attitudes towards the labs, and the processes students use to complete them. We observe student helpseeking strategies, the amount of time they spend performing the lab, and student motivation. Student attitudes towards online physics labs will be accessed through the use of inperson interviews and a pre and post Colorado Learning Attitudes About Science Survey for Experimental Physics (ECLASS). The overall goal is to form a more detailed picture of how students complete online physics labs to improve the quality of online physics instruction. 

C71.00089: The Effects of Heat Exposure Over Various Time Intervals on the Performance Characteristics of Monocrystalline Silicon Photovoltaic Cells Madalynne Forster, Hunter Davis, Noah Cox, Justin L Smoyer, Paul V Quinn With the rise of awareness for climate change and environmental protection, research into alternative energy sources has becoming increasingly important. One of the most popular forms of renewable energy is solar power. Most commonly built solar panels utilize a collection silicon photovoltaic cells to generate electricity. Our research specifically looks into the efficiency characteristics of monocrystalline silicon photovoltaic cells after they are exposed to intense heat for a predetermined amount of time. The cells were heated at temperatures of 190^{o}C, 200^{o}C, and 210^{o}C, for times ranging from 10 minutes to 110 minutes. An analysis of our data shows an average increase in fill fraction with time for all three temperatures. These results indicate a permanent overall increase in efficiency of the cells compared to baseline values. This outcome proves that we do not need to significantly change the process of production of the cells in order to increase the efficiency. 

C71.00090: Optimization of CoFeB Electrodes for Magnetic Tunnel Junctions Gillian Boyce, Suyogya Karki, Jean Anne Incorvia A magnetic tunnel junction (MTJ) is the current standard for converting magnetic information into electrical information. It is formed by sandwiching an insulating barrier between two ferromagnetic electrodes. An external magnetic field is then used to switch the electrodes between parallel and antiparallel magnetic alignment. The focus of this research is to optimize the switching between magnetic states through the optimization of electrode thicknesses, especially when nonconventional barrier materials are used. The goal is to decouple the two FM layer switching fields, which allows readout of two resistance states of the device. The method used is threefold: First, MTJ stacks are grown using sputter deposition. Next, vibrating sample magnetometry is used to test for switching of magnetic alignment. Finally, atomic force microscopy is used to test for interfacial roughness, which could cause the layers to couple and prohibit antiparallel alignment. I will discuss our work developing a method for minimizing the coupling between the FM electrodes by focusing on understanding the interfacial roughness. 

C71.00091: Predicting and Synthesizing Photocatalytic Semiconductor Materials Xavier Quintana, Nathan D Keilbart, Julian Fanghanel, Ismaila Dabo


C71.00092: Effects of Nanoparticle Size and Density on the Critical Current and Creep in (Y,Gd)BCO Films: Comparisons to Strong Pinning Theory Sarah Jones, Roland Willa, Masashi Miura, Serena M Eley Incorporating nanoparticle inclusions into superconducting films is a wellestablished route for boosting current carrying capacity. (Y,Gd)Ba_{2}Cu_{3}O_{7} films containing various nanoparticles have been shown to demonstrate inexplicably slow rates of thermally activated vortex motion (creep, S). Understanding the microscopic source of these slow rates is key to determining how to reduce S in superconductors. In this project, we report on the effects of different sizes and densities of nanoparticle inclusions on the critical current and creep in (Y,Gd)Ba_{2}Cu_{3}O_{7} films. Samples in this study all contain a low density of R_{2}Cu_{2}O_{5} (R = Y,Ba) inclusions (naturally occurring during growth), and each contain either no other nanoparticles, BaHfO_{3}, BaSnO_{3}, or BaZrO_{3} nanoparticles. The data presented was collected from low temperature magnetization measurements in fields of 0.3 T up to 35 T using a VSM at the NHMFL and a local commercial SQUID. 

C71.00093: Design Parameters of Liquid Crystal Elastomer MultiLaminates Kelsey Lynch, JOSELLE MCCRACKEN, Timothy J White Liquid crystal polymer networks or elastomers (LCEs) can be surface aligned into complex orientations that produce cooperative deformation and outofplane shape transformation.^{[1]} When subject to thermal stimuli, thermotropic LCE films actuate and display significant weight lifting capabilities that scale with thickness.^{[2]} Here, we investigate parameters that affect the mechanical output of LCE actuators including thickness, composition, disclination type, and geometrical packing. Specifically, we develop an LCE composition amenable to photoalignment processing that actuates below 70°C. The mechanical response of this material (stroke and force displacement) are contrasted to canonical LCE material systems. The actuation output of the LCE is increased by lamination.^{[3]} A multilaminate LCE material actuator over 1mm in thickness is demonstrated, capable of lifting large objects (>1 lb). 

C71.00094: Solid State NMR Physics Laboratory Rosa Cardenas We report on the progress of the newly developed physics laboratory at the University of the Incarnate Word (UIW). This laboratory is the first physics research laboratory at this institution. It includes a new solid state NMR experimental setup. The experimental setup is comprised of a 400 MHz variable temperature, cryogen free, superconducting magnet manufactured by Cryogenic. It also includes a Tecmag Redstone NMR Spectrometer. This spectrometer is very flexible and therefore many different samples may be analyzed. Field calibration was conducted by using Nuclear Magnetic Resonance (NMR) with liquid D2O. This allowed for successfully tracking the Te NMR signal of an ironchalcogenide FeTeSe sample. The superconducting transition of different purity ironchalcogenide FeTeSe samples will be analyzed in detail. 

C71.00095: Simulation of Efficient Perovskite Solar Cells Madison J Guerrero, Hongkun Cai, Prof Weining Wang While Perovskite popularity has skyrocketed since the efficiency reached 22% in 2018, there is still ample research to be done as to what characteristics and parameters affect the solar cell. In order to obtain a greater understanding of the mechanics of how a perovskite cell becomes more efficient, this project focuses on the simulation program wvAMPS and how parameters alter main characteristics such as Voc (open circuit voltage) and Jsc (short circuit current). The perovskite solar cells were obtained from National Renewable Energy Laboratory. The structure of the solar cell is Ag(120nm)orAu(100nm)/spiroOMeTAD(180200nm)/perovskite(550nm)/mesoporousTiO_{2(200nm)}/compactTiO_{2}(4060nm)/FTO/glass. The measured solar cell parameters are: Voc = 1.06V, Jsc = 16.53 mA/cm^2 , Fill Factor = 63.5% and Efficiency = 11.2%. 

C71.00096: An Algorithm to Optimize the Search for Electromagnetic Counterparts to Gravitational Wave Events Priyadarshini Rajkumar, Alessandra Corsi, Chris Copperwheat, Daniel Perley Our understanding of gravitational wave (GW) events is greatly enhanced by identifying and studying their electromagnetic (EM) counterparts. For nearby GW events with a small localization uncertainty, an effective strategy is to search for new transient sources in previously catalogued galaxies, whose properties are consistent with the GW data. Even with a limited field of view, it is plausible to discover the EM counterparts using an efficient observational strategy. But because many galaxies must be observed and the EM counterparts are faint and fade rapidly, a reliable automatic procedure is crucial to schedule observations efficiently. To meet these challenges, we designed an algorithm in Python that uses a catalogue of nearby galaxies and the threedimensional GW localization map to create a prioritized list of galaxies based on GW errormap probability, observability, and absolute magnitude. We tested our algorithm with past GW events and, within a few minutes, obtained consistent results with previous observations. We conclude highlighting how this algorithm can more generally assist in formulating effective followup plans with various types of small field telescopes at a variety of wavelengths, including radio. 

C71.00097: Machine learning for classifying the chiral phase transition in AdS/QCD Beixi Hao, Sean Bartz AdS/QCD is a phenomenological application of the gauge/gravity duality to stronglyinteracting nuclear matter, including the quarkgluon plasma (QGP). This work uses machine learning to classify the order of the chiral phase transition between ordinary nuclear matter and the QGP. Our machine learning method is a supervisedlearning synthesis of four standard classification algorithms: classification and regression trees (CART), kNearest Neighbors (kNN), Support Vector Machines (SVM) with a linear kernel, and Random Forest (RF). It is trained on a subset of data with known behavior, and tested on the remaining data, with a 100% success rate. We also discuss the application of this machine learning method to the development of an AdS/QCD model featuring a critical point in the QCD phase diagram, which aligns with the current experimental program at Brookhaven National Laboratory. 

C71.00098: EARLY CAREER


C71.00099: Development of a zinc manganese dioxide flow battery David ReyesRamirez With larger penetrations of renewable energy on our electrical grid, there is a need for largescale energy storage devices. A redox flow battery is an electrochemical device with great promise as a largescale energy storage technology given the scalability of the technology and that power and energy output are decoupled. This study aims to incorporate the strengths of flow batteries with the abundance and relatively high safety of manganese dioxide batteries. However, manganese dioxide batteries historically suffer from poor reversibility. To improve reversibility, the effects of different electrolyte additives, as well as the synthesis of manganese nanorods, were investigated. These solutions were then incorporated into a prototype flow battery to address the need for a safe and reliable energy storage device. 

C71.00100: Achieving an efficient control of antiferromagnetic order in artificial layered iridates Lin Hao, Derek J Meyers, Junyi Yang, Hidemaro Suwa, Cristian Batista, Mark Dean, Jian Liu Antiferromagnetic (AFM) materials started to gain traction owing the advantages of reliability, ultrafast dynamics, etc. in spintronic applications. In our recent work, we investigated AFM order in layered iridates, which is a newly established Mott system similar to cuprates but features a strong spinorbit coupling. By building the spinorbit Mott insulators as SrIrO_{3}/SrTiO_{3} superlattices, we gained controllability in the strength and sign of interlayer exchange interaction. This enables one to reach the 2D limit of a magnet, where the ordering temperature is only governed by magnetic anisotropy. The 2D antiferromagnet preserves a hidden SU(2) symmetry, which was first proposed in cuprates but never experimentally realized. Specifically, we unveiled that DzyaloshinskiiMoriya interaction in the squarelattice magnet does not contribute to the spin anisotropy. The extremely strong 2D critical fluctuations enable us to achieve giant AFM responses to subtesla magnetic fields. The observed fieldinduced logarithmic increase of the AFM ordering demonstrates a new pathway for designing efficient AFM spintronics. These results were recently published on Phys. Rev. Lett. [119,027204, (2017)] and Nat. phys. [14, 806810 (2018)]. 

C71.00101: Multimodal xray and electron microscopy of an Allende meteorite sample ChenTing Liao, Yuan Hung Lo, Jihan Zhou, Arjun Rana, Charles Bevis, Guan Gui, Bjoern Enders, Kevin Cannon, David A Shapiro, Henry Kapteyn, Roger Wirth Falcone, Chris Bennett, Jianwei Miao, Margaret Murnane Correlative multimodal microscopy that combines complementary nanoscale imaging techniques is essential for extracting comprehensive chemical, structural, and functional information of heterogeneous complex samples. Advanced electron microscopy provides atomicscale spatial resolution with quantitative elemental composition, while xray microscopy can achieve highresolution imaging of bulk materials with chemical, magnetic, electronic, and bond orientation contrast. In our recent work (Science Advances 5, eaax3009, 2019), we combine xray ptychography and scanning transmission xray spectromicroscopy with 3D energydispersive spectroscopy and electron tomography to perform structural and chemical mapping of an Allende meteorite sample as a model system. We use textural and quantitative elemental information to infer its mineral composition and discuss potential processes that occurred. This multimodal xray and electron microscopy of the same sample overcomes the limitations of individual imaging modalities and opens up a route to future multiscale microscopies of complex functional materials and biological systems. 

C71.00102: Rationale Design of Polymeric Materials for Biological and Energy Applications using Multisclae Simulation Methods Vaidyanathan Sethuraman, David Clark Morse, Kevin D Dorfman Two broad areas are investigated in this poster: (i) Selfassembly of Methylcellulose in Solution: We employ coarsegrained molecular dynamics simulations to show that the current theories of stacked toroid model for fibril formation is valid only at certain polymer concentrations. Rather, we showed the existence of a nucleation mechanism and the importance of conformational fluctuations for systems containing randomly coiled chains. We also show how the conformational and structural characteristics change with grafting the backbone with flexible polymers; (ii) Polyelectrolyte Complexation: We utilize implicit solvent coarsegrained molecular dynamics to probe the influence of charge sequence along the polymer backbone, on their adsorption efficacy onto grafted polyelectrolytes. Our work show that adsorption is strongest when both the grafted and the free polyelectrolyte in the solution possess a block charge sequence architecture and is weakest when both the grafted and the free polyelectrolyte possess an alternating architecture. We then showed that the sequence dependence on adsorption efficacy is enthalpic in nature and not entropic. We also show the effect of influence of charge sequence on polydisperse polyelectrolytes. 

C71.00103: Proximity effects in twodimensional transitionmetal dichalcogenide materials for quantum information science Christopher Lane, JianXin Zhu Significant strides have been made towards the storage and processing of quantum information. However, scalable robust material platforms are scarce. The twodimensional (2D) transitionmetal dichalcogenides provide a possible path forward due to their valley degrees of freedom, which may be probed by circularly polarized light. Unfortunately, these levels are commonly degenerate in energy. Therefore, to create a viable platform for valleybased qubits, it is crucial to break time reversal symmetry in a controllable manner, allowing for direct manipulation. Using stateoftheart ab initio techniques, we demonstrate that controllable valley splitting can be achieved through a magnetic exchange proximity effect generated by a ferromagnetic 2D material substrate. Furthermore, by introducing vacancies into the transitionmetal dichalcogenide layer, longlived twolevel impurity states may be stabilized. This approach reveals a new path towards the rational design of new complex multilayer systems for direct application in quantum information technologies and spinoptoelectronic devices. 

C71.00104: Simultaneous Study of Structure and CorrelationDriven Transitions via Xray Standing Waves Matthew J. Wahila, Galo J. Paez, Christopher Singh, Nicholas F Quackenbush, Hanjong Paik, Darrell Schlom, TienLin Lee, WeiCheng Lee, Louis F. J. Piper The possibility of decoupling electronic phenomena from those of the lattice has been a hot topic when discussing correlated metalinsulator transition materials such as VO_{2}, NbO_{2}, or V_{2}O_{3}.[1] A mainly electronic transition could enable ultrafast switching, thin film electronics, with little risk of the inevitable physical degradation associated with bulk structural transitions. However, the roles of structural (Peierls) and electron correlation (Mott) effects in driving these transitions continue to be debated in the literature.[2] Using xray standing waves (XSW) and high quality epitaxial thin films, we have now concurrently investigated both the structural and electronic transition within some of these correlated materials using a single technique, directly measuring their simultaneity or lack thereof for the first time. We discuss these results and their wider implications. 

C71.00105: Electronic Correlation Effects on the Fermi Surface Topology of dPlutonium Roxanne Tutchton, Weiting Chiu, Robert C Albers, Gabriel Kotliar, JianXin Zhu Due to its position at the boundary between the light and heavy actinides, Pu has exotic physical properties that are complex and challenging to model. The difficulties in obtaining a full theoretical understanding for this elemental solid stem from the transitional characteristics of Pu5f orbital electrons and understanding the role of the fluctuating magnetism in the electronic structure. Focusing on the δphase of elemental Pu, we perform a careful comparison of Fermi surface topology calculations using DFT and DFT+U methods. The de Haasvan Alphen (dHvA) frequencies at the Fermi surface and band masses are calculated in both magnetic and nonmagnetic states. We also analyze the effective mass enhancement due to 5felectron correlation effects with DMFT as compared to the Gutzwiller approximation (GA). The comparison study will be helpful for future experiments to validate theoretical modeling. 

C71.00106: van der Waals photothermoelectric effect in atomic layer heterojunctions Yunqiu (Kelly) Luo, Tong Zhou, Mahesh R Neupane, Alex Matos Abiague, Ryan BaileyCrandell, Michael J Newburger, Igor Lyalin, Igor Zutic, Roland Kawakami Twodimensional (2D) van der Waals (vdW) heterostructures provide exceptional opportunities for new physics and devices due to their unprecedented ability to tune the electronic, optical, magnetic and spintronic properties by atomic layer stacking and electrostatic gating. Harnessing this versatility requires a fundamental understanding of lightmatter interactions and establishing new functionalities for photoncharge and photonspin conversions. Here, we report the first observation of a highlytunable vdW photothermoelectric effect in dualgated MoS /graphene junctions with a striking multiplepolarity switching of photocurrent as a function of junction bias and carrier density. In stark contrast to photovoltaic effects arising from excitonic absorption in MoS_{2}, the vdW photothermoelectric effect originates from photoexcitation of hot electrons in graphene and thermoelectric transport across the vdW junction. Systematic studies of photoconductance as a function of photon energy and intensity reveal vdW photothermoelectric effect as the dominant mechanism for photocurrent generation at room temperature, as opposed to excitonic absorption. These findings provide an important step for understanding and control of vdWinterface devices. 

C71.00107: New Approaches and Observations in Scaled Contacts for 2D FETs Zhihui Cheng, Hattan Abuzaid, Yifei Yu, Shreya Singh, Linyou Cao, Curt Richter, Aaron Franklin Atomically thin 2D crystals are promising channel materials for extremely scaled fieldeffect transistors (FETs). For devices at the scaled regime, both channel and contact length must be scaled, with channel length being the distance from source to drain contacts and contact length being the length of the source/drain covering the 2D semiconductor channel. Contacting 2D materials at these scaled contact lengths (< 30 nm) has rarely been pursued or studied in depth. Moreover, the device community has not yet determined how contacts can be scaled without causing significant degradation in device performance; i.e., how long is the transfer length, below which current crowding effects appear? Here, we demonstrate new measurement approaches and results for determining the transfer length of MoS_{2} FETs by physically scaling the contact length. We found that, contrary to previous reports, top contacts can be scaled to ~20 nm without obvious degradation in transistor performance. Our data from measurements of over 100 devices with different contact lengths statistically imply that contact resistance variation increases in the scaled contact regime. Our work illustrates the impact of current crowding in scaled contacts and the ultimate scalability of metal2D contact interfaces. 

C71.00108: Investigation into form factors for mechanicalresonancebased methods of information storage Christopher Hakoda, Cristian Pantea, Vamshi Krishna Chillara Nontraditional information storage has become increasingly ubiquitous as a means of providing interactive, environmentspecific information. With this in mind, we have investigated potential formfactors for a PZTbased information storage method that has visibly indistinguishable features for improved security. By manipulating the poling of PZT transducers, we developed a frequencydependent, embedded array of transducers which, when excited at the relevant frequencies, reveal an engineered velocity profile. This velocity profile is then measured using a scanning laser Doppler vibrometer and decoded. Since this storage method is capable of storing frequencydependent information, it can also store multiple layers of information that can be easily separated by applying a fastFourier transform. These multiple layers can be used for storing additional information or further hiding the encoded data. Two potential form factors are simulated and discussed in this proceedings, one has a flat profile while the other has a cylindrical profile. 

C71.00109: Spontaneous thermal Hall conductance in superconductors with broken timereversal symmetry Firat Yilmaz, Sungkit Yip The thermal Hall conductivities(THCs), $\kappa_{ij}$s have extensively been studied in recent condensed matter experiments. THC can spontaneously become nonzero for a timereversal symmetry (TRS) broken system, and have a contribution from topologically protected edge states. In this talk, we focus on an additional bulk effect, the impurity pair breaking mechanism(IPM) in superconductors (SCs). Previously, the THCs were calculated for the chiral pwave[12] SCs for point impurities. Motivated by dwave TRS broken SCs; URu$_2$Si$_2$, SrPtAs including Sr$_2$RuO$_4$ which is recently suggested to be also possibbly, we calculate THCs at finite temperatures and for finite size impurities using the nonequilibrium quasiclassical Green's functions. 

C71.00110: Do Levinthals arguments lead to a paradox for Si_{20}H_{20}? Deb De, Bastian Schaefer, Stefan A C Goedecker Levinthal argued that the folding of a protein should require a time longer than the age 

C71.00111: Understanding the acoustic emission from gas bubble dynamics: a signature of CO_{2} leakage Hung DOAN The identification and characterization of CO_{2} leakage signatures in water and other fluids are of interest in the geophysical study of geysers and aquifers. As several DOE programs are investigating the feasibility of operationally injecting CO_{2} into the subsurface, detecting and characterizing the signatures associated with the interaction of CO_{2} with water shows important implications for monitoring large scale Carbon storage. This project proposes the development of a laboratoryscale test bench to carry out experimental studies of the acoustic emission emanating from gas bubble dynamics in a biphasic (water and gas mixture) fluid system. Different air bubble sizes, varying from 1 cm to 10 cm, are injected from the bottom of a water bath. As the bubbles migrate to the top, the vibrational response of those bubbles is captured by an acoustic pressure sensor placed within the fluid. The interaction is expected to be dependent on the size of the bubble, which can be characterized using the recorded acoustic signal. The result provides a noninvasive technique for characterizing the air bubblesize in the water/gas system and enables us to develop a framework for determining signatures pertaining to the presence of CO_{2} in water. 

C71.00112: Experimental Demonstration of a Superconducting 0π Qubit Andras Gyenis Encoding a qubit in logical quantum states with wavefunctions characterized by disjoint support and robust energies can offer simultaneous protection against relaxation and pure dephasing. Using a twodimensional circuitquantumelectrodynamics architecture, we experimentally realize a superconducting 0π qubit, which hosts protected states suitable for quantuminformation processing. Our multitone spectroscopy measurements reveal the energy level structure of the system, which can be precisely described by a simple twomode Hamiltonian. The parity symmetry of the qubit results in chargeinsensitive levels connecting the protected states, allowing for logical operations. The measured relaxation (1.6 ms) and dephasing times (25 μs) demonstrate that our implementation of the 0π circuit not only broadens the family of superconducting qubits but also represents a promising candidate for the building block of a faulttolerant quantum computer. 

C71.00113: Longlived Floquet phases in interacting threedimensional topological semimetals via bicircular laser fields Thais Victa Trevisan, RobertJan Slager, Peter Orth The use of carefully tailored light fields to manipulate quantum states of matter is an important technique in condensed matter physics. By coupling to the electronic degrees of freedom, they can induce electronic phases that were otherwise absent, for example, by selectively breaking a certain symmetry. One important example is the breaking of timereversal symmetry by circulary polarized light, which can lead to a photoinduced Hall effect or the splitting of a threedimensional Dirac node into Weyl nodes. Interestingly, it was recently showed that bicircular laser fields can also break spatial symmetries such as inversion or rotation symmetries, thereby inducing a charge (or spin) density wave order. Importantly, the density wave order can persist even after the light field is turned off, leading to a longlived lightinduced phase. This idea was recently explored in graphene, where it was shown to lead to a longlived Floquet chargedensity wave phase due to a dynamic synchronization transition. Here, we report our findings on coupling bicircular laser light to threedimensional materials in order to induce spin and/or charge density wave phases. We specifically discuss the effects on topological phases of matter in Dirac and Weyl semimetals. 

C71.00114: Band engineering for quantum simulation with superconducting circuits Christie Chiu, Andrew Houck Quantum simulation has been implemented on a variety of experimental platforms such as neutral atoms, ions, quantum dots, and superconducting circuits, each offering unique features. Superconducting circuits can and have been used to realize artificial photonic materials in a wide range of lattice geometries and graph connectivities, due to the flexibility of onchip fabrication. In addition, photonphoton interactions are possible using nonlinearities such as superconducting qubits, leveraging the vast toolkit developed for quantum computation. Here I report on recent progress towards engineering flat bands for studies of strongly correlated manybody physics. 

C71.00115: Using Machine Learning to Classify Phase Behavior of Oil/Water/Surfactant Systems Shiyan WANG, Nathan Schultheiss, Sangtae Kim According to BP Statistical Review of World Energy in 2019, total oil production from the US in 2018 was about 15 million barrels per day (MBPD). Thanks to the booming shale oil production, United States has become the world’s top oil producer. In fact, estimates show that up to two thirds of conventional crude oil in mature fields remains unproduced due to the physics of fluid flow. The techniques of chemical enhanced oil recovery could overcome the physical force holding hydrocarbons, and turn these accumulations into oil reserve, which would enhance the US energy security and maintain economic growth. For the oil/water/surfactant system, the goal is to form a microemulsion phase achieving the lowest interfacial tension, which increases the capillary number and dramatically recovers the remaining oil fraction within the pore. Therefore, it is critically important to understand the phase behavior for the oil/water/surfactant systems. In collaboration with Pioneer Oil Company, our current effort is to optimize the selection of surfactants and the constituents of the surfactant blend, which turns to be a high dimensional problem. In addition to the conventional analysis, we employ machine learning techniques to solve the system as a multinomial classification problem. 

C71.00116: Resonant Raman Spectroscopy of the Chiral Antiferromagnet CoNb3S6 Nora Hassan, Thuc Mai, Amber McCreary, Nirmal Ghimire, Angela Hight Walker


C71.00117: Physicsbased models and simulations of cancer drug response in solid tumors Aminur Rahman, Souparno Ghosh, Erdi Kara, Eugenio Aulisa Over the past few decades, cancer related deaths have fallen significantly as noted by the National Cancer Institute. However, assessing cancer treatments is still predominantly a trial and error process. This approach may result in delays to administer the correct treatment, the use of more invasive procedures than necessary, or an increase in toxicity due to superfluous treatments. Although these procedures may end up saving the patient, the treatment may also have an adverse effect on their quality of life. Relaible mechanistic models of drug response can potentially be used to aid oncologists and doctors in deciding on an optimal treatment strategy for the patient. We develop a modeling framework for tumor ablation, and present coupled transport  population models of varying complexity. First, we present a radially symmetric drug diffusion and binary cell death model, which produces a theoretical dose for optimal effiacy to toxicity ratios. Further, we investigate inhomogeneous  anisotropic drug diffusion, and develop an algorithm to locate the optimla injection points. Finally, we derive stochastic tumor population models that can be coupled to transport models in our framework. Importantly, the mechanistic models outperform datadriven models in statistical tests. 

C71.00118: A Patterning Approach to Untangling Critical Interface Phenomena with InSitu Resonant Scattering Isvar Cordova, Guillaume Freychet, Romain Geneaux, Cheng Wang Resonant soft xray scattering (RSoXS) is a powerful spatiochemical mesoscale characterization tool that is often overlooked across the field of interfacial science. Herein, we present a simple, yet highly sensitive, patterning approach for interface characterization that takes advantage of the physical processes intrinsic to small angle resonant Xray scattering in order to selectively probe and enhance signals from interfacial regions of a vast array of material systems. Using several case studies, we show how patterns with simple nanoscale features can be used to 1) decouple the bulk from the interface scattering signal, 2) extract interfacial morphology with subnm precision, and 3) collect sitespecific xray absorption spectra (XAS). 

C71.00119: Tuning block copolymer rheology and structure via low strength magnetic fields Karthika Suresh, Michelle Calabrese The control of block polymer (BCP) structural ordering is of significant scientific interest because of their wide applications including nanotemplates, drug delivery and biomineralization. BCP properties have been controlled using various external fields including electric, magnetic, and shear fields, and via plasticizing additives, interfacial effects, and thermal methods. To control ordering in BCPs using magnetic fields, previous studies had used field strengths (≥5T), liquid crystalline mesogens, high magnetic susceptibility anisotropy groups or combinations therein. Here, we show anomalous behavior upon application of low strength magnetic fields (≥0.1 T) in coilcoil BCPs. Magnetoshear rheology shows up to a six order increase in modulus upon the field application. This magnetic response is a function of temperature, concentration, field strength, ionic content and shear strain. A minimum molecular weight and block length are required for this liquid to gel transition via low strength magnetic field. In situ small angle scattering (SAXS and SANS) and imaging techniques showed fieldinduced orientation in the BCPs and this orientation direction can be tuned by changing the direction of field lines. 

C71.00120: PHYSICS EDUCATION


C71.00121: Can Fermi energy be estimated experimentally? Chetan Kotabage, Ashutosh Abhyankar Fermions, particles with half integral spin, follow FermiDirac distribution. For free electron gas at absolute zero, Fermi energy is the energy of highest occuped level by electron. For n, which is density of free electrons, Fermi energy can be estimated by E_{F}= h^{2 }(3π^{2}n)^{2/3}/(8mπ^{2}) [1]. Theoretical calculation of Fermi energy of a metal involves estimation of density of electrons utilizing number of valence electrons. Experimentally, Fermi energy can be estimated by measurement of density of electrons in Hall effect measurement at room temperature. The measurement at room temperature serves as a good approximation because of very less difference between electron distribution at 0K and 300K. 

C71.00122: Two Content Pathways in Presenting Electromagnetism in Introductory AlgebraBased Physics Textbooks Liang Zeng, Yi Zeng, Guang Zeng Vector cross products play a fundamental role in determining the directions of electromagnetism in introductory physics courses. After examining thirteen introductory algebrabased physics textbooks, we found authors adopt the following two content pathways in presenting the electromagnetic phenomena: Over 90% of the textbooks follow pathway one which presents only algebraic formulas and mnemonic techniques for right and lefthand rules. Scarcely few follow pathway two, which presents vector cross products as a mathematical model and reinforces this model by presenting the specific cross product formula for each electromagnetic phenomenon. Physics instructors teaching college physics courses similarly present electromagnetism using these two content pathways. In light of Bloom’s taxonomy of educational objectives and constructivist learning theory, we recommend the second pathway. 

C71.00123: Using Group Exams to Address Persistent Intuitively Appealing but Incorrect Student Reasoning Alistair McInerny, Lioudmila Kryjevskaia Many students tend to provide intuitively appealing (but incorrect) responses to some physics questions despite demonstrating (on similar questions) the formal knowledge necessary to reason correctly. While these inconsistencies are typically persistent even in active learning environments, we believe that adding a group component to the exam may engage students sufficiently to resolve these instances of inconsistent reasoning. In our study, students were given opportunities to revisit their answers to questions known to elicit strong intuitively appealing (but incorrect) responses in a collaborative group component of an exam immediately following a traditional individual component. Students discussed their responses with group members but were required to submit their own answers and reasoning. On this poster, we examine the effectiveness of a collaborative group exam approach in addressing and resolving inconsistencies in student reasoning and will compare the effectiveness of this approach to a more traditional peer instruction technique. 

C71.00124: Incorporating realistic aspects of experimentation into senior physics labs Kirstin Purdy Drew Here we present design changes to the senior physics lab course at Penn State, which were implemented in order to increase student engagement with modeling,experiment design, and the writing process in our lab curriculum. The goal of these changes was to restructure the course to emphasize planning, prediction, and assessment of experimental data during an experimental process, in mimicry of the scientific research process, while still providing students with exposure to a breadth of experiments and experimental techniques which are historically a required part of the course. Both structural and content changes made in the course will be presented along with initial assessment of changes in student perceptions and critical thinking skills. 

C71.00125: INDUSTRIAL AND APPLIED PHYSICS


C71.00126: Machine Learning Towards Optical Spectrum Estimation Using Nanomaterial Thin Films Davoud Hejazi, Shuangjun Liu, Amirreza Farnoosh, Sarah Ostadabbas, Swastik Kar Some of the major challenges in optical spectrum estimation include the necessity to create an array of thousands of identical photodetectors, or intricate mechanical systems that make the estimation system bulky and expensive. Using the spectral transmittance of an array of 11 solutionprocessed nanomaterial thin film filters fabricated from two layered semiconducting materials, MolybdenumDisulfide and TungstenDisulfide, we have estimated the wavelength of any incoming light in a wide spectrum range. By applying machine learning techniques we have used the variations in spectral transmittance of nanomaterials as the alternative method for optical spectrum estimation. We have studied the efficacy of various machine learning algorithms including knearest neighbors, artificial neural networks, support vector machines, and Bayesian statistics in spectrum estimation problem and identified the key advantages and limitations of each algorithm for realtime applications such as accuracy and speed. Furthermore, we have modeled the temporal drift of filters' spectral transmittance over a period of one year and showed that it is possible to overcome the driftinduced inaccuracies over time using a modeled drift function. 

C71.00127: Improve the synaptic performance of resistive switching devices through interface engineering Yu Shi, Rabiul Islam, Guoxing Miao Transition metal based resistive switching devices (like HfO_{2}, TiO_{2) }has been shown to be a good candidate for neuromorphic computing for its bioinspired synaptic properties, however, the nonlinear conductance change synaptic behaviour prohibits further improvement due to poor accuracy of neural network training. Here, we provide a way to eliminate the intrinsic nonlinearity through electrodeoxide interface engineering, including oxygen profile control and oxide heterostructure stacking, which can improve the neural network training accuracy and shorten the training time. 

C71.00128: High Thermoelectric Performance in Hexagonal 2D PdTe_{2} Monolayer at Room Temperature Brahim Marfoua, Jisang Hong Motivated by the recent fabrication of hexagonal PdTe_{2} monolayer, we investigated the thermoelectric properties of the hexagonal and pentagonal PdTe_{2 }structures using two approaches. The pentagonal monolayer has not been synthesized yet. The hexagonal layer had an indirect band gap of 0.17 eV while the pentagonal structure had an indirect bandgap of 1.18 eV. By applying the semiempirical Wiedemann–Franz law to calculate the electronic thermal conductivity, we found that both hexagonal and pentagonal structures had very high ZT more than 3. However, the Wiedemann–Franz law underestimated the electronic thermal conductivity and this resulted in high ZT. Thus, we employed the Boltzmann transport equation for the electronic thermal conductivity. At high temperature ( > 500 K), the pentagonal PdTe_{2 }structure showed a better thermoelectric performance than the hexagonal structure. However, both structures displayed the same ZT of 0.8 at 300 K. We propose that the hexagonal PdTe_{2} can be a potential high performance thermoelectric material at room temperature. 

C71.00129: Textile Thermoelectric Generator Based on Carbon Nanotubes Fariba Islam, Nabila Fairuz, Ahmed Zubair Smart textile based on seamless device integration into clothing will dominate the wearable technology field in the near future. Carbon nanotubes (CNTs) are a favorable candidate for use in these flexible and wearable electronic devices due to tunability of their electrical and thermal properties, mechanical strength, and lightweight. The wearable devices demand wearable microsources of energy. Here, we propose a textile thermoelectric generator based on CNT that can utilize waste heat to generate power. The generator is fiberstructured to make it easily woven into clothing. We simulated a ~5 cm long fiber structured generator with pn junctions at every 3 mm interval based on CNTs. To model CNTs, experimental data were used in our simulation. This generator generates a thermoelectric voltage of ~55 μV for just a 1 K temperature difference. The thermoelectric figure of merit, ZT for this CNT based device was smaller than previously reported materials. However, it is possible to fabricate CNT based devices with large ZT by proper doping and utilizing the Van Hove singularities in the density of states of CNTs. 

C71.00130: Structural Phase Transition of Multilayer VSe_{2} XIONG WANG, Dian Li, Xiaodong Cui, Chuanhong Jin Vanadium diselenide (VSe2), a member of the transition metal dichalcogenides (TMDs) family, is emerging as a promising twodimensional (2D) candidate for the electronic and spintronic device with exotic properties including charge density wave and ferromagnetism. The bulk crystal VSe2 exists in a crystallographic form of 1T phase with metallic behavior. In this paper, we report a structural phase transition of multilayer VSe2 from 1T to 2H, which occurs at about 650 K, accompanying a metalinsulator transition. The phase transition is verified by Raman spectra, as different polymorphs have different Raman signals related to different characteristic vibration modes. The electrical characteristics are also studied on VSe2 nanoflakes, as the phase transition occurs along with the metalsemiconductor transition, which is consistent with the electronic band structure calculation. The results of insitu selected area electron diffraction (SAED) is are accord with our simulated diffraction patterns, which is strong evidence of the structural phase transition. Moreover, we observe that the 2H phase is more thermodynamically stable than the 1T phase at the multilayer level. 

C71.00131: Investigating the metal to insulator transition in crystalline NbO_{2} for neuromorphic computing applications Galo Paez Fajardo, Matthew J. Wahila, Jatinkumar Rana, Brooks Tellekamp, William A. Doolittle, Louis F. J. Piper The metalinsulator transition (MIT) of NbO2 is promising for technological applications where a selfregulated resistivity is needed like in neuromorphic computing. Though the Mott nature (electron correlation) of the MIT of NbO2 arises purely by comparison to VO_{2}, the actual transition mechanism in NbOxbased memristors remains unclear mainly due to the degree of participation of multiphases of niobium oxides, likely induced after electroforming. By investigating phasepure, crystalline NbO2, we avoid the uncertainty created in electroformed NbOxbased devices. Using surface sensitive techniques like LEED, HAXPES, and LEEM on NbO2(440)/Al2O3(006) thin films, we show that the phase transition does not extend to the film surface. XPS of the crystalline NbO2 reveals a secondorder Peierls transition in the bulk, in agreement with DFT results, indicating electron correlation effects do not play a significant role. In addition, the observed temperature dependence of the NbNb dimer distance which controls the NbO2 resistivity suggests that the switching of future phasepure NbO2 memristors could be controlled by resistive heating in an analog rather than digital fashion. 

C71.00132: Magnetically driven carbon nanotubes for a highly efficient mechanical single cell damage. Victoria Gabriele, Krzysztof Kempa, Michael Naughton, Thomas Seyfried Magnetized carbon nanotubes have previously been demonstrated as excellent candidates for the nanospearing transfection technique. In the presence of the moderate, spacially varying magnetic field, these magnetic nanorods exert motion, capable of piercing cell membranes, and allowing for highly efficient drug delivery. Here we study the possibility of enhancing this nanospearing technique, by varying magnetic strength and its timespace patterns, in order to inflict a highly efficient and selective, single cell mechanical damage. 

C71.00133: Quasiparticle and Optical Properties of Bulk and Monolayer Zirconium Disulfide Gabe LopezCandales, Greis Julieth Cruz Reyes, Zhao Tang, Peihong Zhang Zirconium disulfide (ZrS2) is a member of layered transition metal dichalcogenide (TMD) family that has rich and versatile chemical and physical properties. Despite much recent renewed interest in ZrS2, especially in fewlayer ZrS2 systems, an accurate and systematic understanding of the quasiparticle and optical of ZrS2 from monolayer to bulk phase is still lacking. In this work, we present a fully converged GW+BSE study of the quasiparticle and optical properties of monolayer and bulk ZrS2, aiming at illustrating the subtle interplay between structural and electronic properties and the importance of the convergence issues in 2D manybody perturbation calculations. 

C71.00134: AbInitio Computations of Electronic and Related Properties of cubic Magnesium Silicide (Mg_{2}Si) Dioum Allé, Blaise Ayirizia, Yuriy Malozovsky, Diola Bagayoko We have performed abinitio, selfconsistent calculations of electronic, transport, and bulk properties of cubic magnesium silicide (Mg_{2}Si). Our computations employed the local density approximation (LDA) potential of Ceperley and Alder and the linear combination of atomic orbital (LCAO) formalism. We followed the BZWEF method to reach the ground state of the maerials, verifiable, without using overcomplete basis sets. For a room temperature lattice constant, our calculated, indirect band gap, from Γ to X, is 0.86 eV. We discuss the total and partial densities of states, electron and hole effective masses, and the bulk modulus. 

C71.00135: Abinitio Calculations of Electronic Properties of Tin Selenide (SnSe) Yuriy Malozovsky, Shaibu Mathias, Diola Bagayoko We present results from abinitio, selfconsistent density functional theory (DFT) calculations of electronic properties of tin selenide (SnSe) in the orthorhombic B16 crystal structure. We utilized a local density approximation (LDA) potential and the linear combination of atomic orbital (LCAO) formalism. Our calculations performed a generalized minimization of the energy to reach the ground state, as required by the second DFT theorem. This process ensures the full, physical content of our findings that include electronic energy bands, total and partial densities of states, and electron and hole effective masses. 

C71.00136: Calculations of third order nonlinear susceptibilities focused in two photon absorption on semiconductors. Alan Bernal, Brandon Furey, Michael C Downer, Bernardo Mendoza Santoyo We presented the calculation of nonlinear third order susceptibility focused on Twophoton absorption phenomena (TPA) on bulk crystal semiconductors. Our calculation considers the longitudinal gauge approximation to the interaction field, the nonlocal part of the crystal potential and the scissor operator as correction to LDA energies calculations. 

C71.00137: Observation of B 1s trion and A 2s trion in 2d limit Tengfei Yan, ke xiao, Xiaodong Cui The distinct excitonic effect in twodimensional (2d) layered material attracts lot of attentions in recent years. The largely reduced screening effect in 2d materials allows tightly bonding exciton. With gate tunable photoluminescence spectrum, we observe B 1s trion and A 2s trion in hBN capsuled MoSe_{2}. The two states show much larger valley polarization compared with their low energy counterparts A 1s exciton and trion. 

C71.00138: Excited carrier relaxation in GaAs by midIR pumpprobe spectroscopy Roisul Galib, John A Tomko, David Olson, Ashutosh K Giri, John T Gaskins, Patrick Hopkins Ultrafast laser spectroscopy is a versatile technique that is commonly used to both understand and manipulate carrier scattering mechanisms in semiconductors. We report the observation of excited carrier relaxation times in GaAs using optical pump mid IR probe spectroscopy. We find a sharp change in relaxation times occurs at the intervalley transitions of GaAs. Our results also show the relaxation times becomes faster with increasing photoexcitation fluence. These results provide direct evidence that excited carrier decay at greatly different rates based on their energy relative to the conduction band minimum. These findings provide additional insight into the energydependent nature and rate of phonon emission during electronic relaxation. 

C71.00139: Temperature dependent vibrational modes of TNT and CL20 cocrystal in terahertz regime Abdur Rahman, Towfiq Ahmed, Abul Azad, David Moore We employed terahertz time domain spectroscopy (THzTDS), a noninvasive technique, in the range of 0.30 THz to 2.50 THz to measure the effective dielectric properties of a 1:1 molar ratio cocrystal of TNT and CL20 in the temperature range 150K to 400K. We observed two distinguished absorption peaks at 0.80 THz and 1.3 THz at or below room temperature. The absorption peaks disappear at higher temperatures. We extracted the dielectric constants of the cocrystal using effective medium theories. 

C71.00140: Pointofcare ultrahigh sensitivity magnetic lateral flow assay Mohammad Khodadadi, João Trabuco, Long Chang, Katerina Kourentzi, Richard Willson, Dmitri Litvinov Today, many highly quantitative biomarker detection tools for medical diagnostics are readily available in stateoftheart centralized clinical laboratories. However, there remains a critical need for inexpensive, versatile, and highsensitivity diagnostic platforms which can bring the performance to the point of care (POC) or doctor’s office. Our team has developed an ultrasensitive point of care biosensor based on the miniaturized inductive detector of magnetic reporter nanoparticles (10^{10} emu detection limit) in a test line of a lateral flow assay (like a pregnancy test). This technology represents a new general biosensor platform that can be broadly useful in various areas of molecular diagnostics, therapy monitoring, biomarker detection, and biomedical research. The biosensor prototype performance was evaluated using a standard hCG model system with well established LFA immunochemistry based on readily available, wellcharacterized, and inexpensive antibodies. The first target after proof of concept is to make a biosensing platform for detecting the recurrence of prostate cancer. 

C71.00141: WITHDRAWN ABSTRACT


C71.00142: Obstacles to Undergraduate Research in Thin Film SemiConductor Characterization: The Creation of Inexpensive Hall Measurement Apparatus Oluwasekemi Odumosu The goal of my project was to grow and characterize thin semiconducting ZnO films grown on PET plastic via pulsed laser deposition (PLD) with a KrF laser. To characterize the electrical properties of these films, I had to create an automated Hall Measurement apparatus, as I did not have access to industrial equipment due to its unfeasible cost. The apparatus required a few components: I started by creating a Labview program to interface with an ArduinoMega, which operates a 16switch relay. This relay was then connected to a nanovoltmeter, current source, and my sample film (which would be in a uniform magnetic field for some measurements). Labview would then compile the data into a .csv file, which my Python code would interpret and record measurements for the sheet resistance, bulk resistivity, semiconductor type, sheet carrier density, bulk carrier density, and hall mobility. The apparatus functions correctly, but improvements need to be made to get consistent data. 

C71.00143: Thermoelectric effect in suspended Bi_{2}Se_{3} grown by molecular beam epitaxy on GaAs(111)A Donguk Kim, Chanuk Yang, Joon Sue Lee, Yun Daniel Park Bi_{2}Se_{3} is well known as an efficient thermoelectric (TE) material. We report growth optimization of Bi_{2}Se_{3} thin films and thermoelectric study of suspended Bi_{2}Se_{3} beam structures. The Bi_{2}Se_{3} thin films were grown on GaAs(111)A substrates by molecular beam epitaxy (MBE) and confirmed by (00n) series peaks of xray diffraction (XRD) that the material was grown along the caxis of GaAs(111)A. Optimizing the desorption process of GaAs(111)A surface and growth conditions of GaAs buffer layers leads to low RMS roughness and lessdefective structural aspect. Using the optimizied Bi_{2}Se_{3} films, we realize the suspended beam structures with minimal heat dissipation to GaAs substrate. The beam structures are fabricated by selective wet etching, and on the two membranes, platinum heaters and voltage channels are patterned to measure the thermoelectric effect, the conversion of temperature difference to electric voltage. Nanomachining technique enables to calculate the dimensionless figure of merit (ZT) of Bi_{2}Se_{3} with minimal environmental factors. 

C71.00144: High quality Tantalum pentoxide thin film growth and its application for low loss nonlinear waveguide JiaWei Liu, ChaoHong Lin, TEKENG WANG, FuYan Yan, ZiDe Xie, MinHsiung Shih, ChaoKuei Lee Tantalum pentoxide (Ta_{2}O_{5}) of a large bandgap material has shown its potential for Si photonics due to its low absorption loss coefficient in visible to infrared regions, high Kerr coefficients, and nonlinear absorption(TPA/FCA) free. Development of large scale high optical quality thin film for integrated photonics is therefore desired. In this work, by using egun evaporation, large scale Ta_{2}O_{5} thin film growth was performed. Beside the measurement of xray and Ramen pattern for identifying the structure, the AFM and SEM results all show the grown thin film with high quality. In addition, a lowloss and highQ Ta_{2}O_{5} based microring resonator was fabricated and characterized. The propagating loss of 0.3 dB/cm was obtained and unloaded quality as high as 300000 was accordingly estimated. This is, in our knowledge, the largest unloaded quality for Ta_{2}O_{5} waveguide. This all show that electron beam thermal evaporation (Egun) grown Ta_{2}O_{5} film is with great potential for photonic integrated circuit. 

C71.00145: WITHDRAWN ABSTRACT


C71.00146: Dry surface cleaning of twisted bilayer graphene and angle dependent oxydation by UV irradiation. Jin Hong Kim, MOHD MUSAIB HAIDARI, Jin Sik Choi Since production of single layer graphene (SLG) by mechenical exfoliation, it has been focal to many researches thanks to its extraordinary electrical conductivity and surface to volume ratio. these characteristics of graphene have benefit for apply gas sensor devices. Recently, twisted bilayer graphene (tBLG) attracted much attention of its extra ordinary physical properties, especially for its twist angle optoelectircal dependant characteristic. specifically, the magic angle (~1.1°) which shows super conducting characteristics. Moreover, tBLG shows higher mobility and conductivity than SLG. However, stacking two layers of sigle crystaline SLG has been reported to show side effect of introducing interlayer impurities during transfer process. Furthermore, Impurities of graphene surface, such as PMMA residues, degrade electrical conductivity and mobility. Here we report a CVD synthesis of clean interlayer tBLG to containing various twist angles. Top layer of tBLG was cleaned and oxidized by angle dependency under UV irradiation at ambient condition and characterized by Raman and electrical properties. We suggest that UV cleaning is the most effective method for surface cleaning of graphene. Also, we expect a correlation between oxidation rate and twist angle. 

C71.00147: High transmittance Er doped ZnO thin films as electrodes for organic lightemitting diodes shi yingli, ChiChung Ling Transparent conducting oxides (TCO) have attracted great attention since the first demonstration in 1907 by Baedeker. TCO thin films with high transparency and electrical conductivity have been widely used in optoelectronic devices, such as thinfilm transistors, perovskite solar cells and light emitting diodes (LEDs). Er doped ZnO films exhibit higher optical transparency (~95 %) than other reported metal elements doped ZnO TCO thin films. The effect of Er doping concentration on photoelectric properties of ErZO thin films was investigated in the range of 02.0 wt.%. The Er impurity substitutes the Zn site and Er_{Zn} serves as charge donor in the ZnO crystal structure, thus resulting in the improvement of ntype conductivity as compared with intrinsic ZnO thin films. The optimized ErZO thin films present the low resistivity of 3.4×10^{−4} Ω/cm, high carrier concentration of 5.9×10^{20} /cm^{3} and high visible optical transmittance (~93%) when the Er content is 1.0 wt.%. The ErZO thin films were used as transparent anodes to fabricate organic lightemitting diodes (OLEDs). Impressively, with the ErZO as anode, the current efficiency of the OLEDs device can reach as high as 86.5 cd/A, which was increased by 14% when compared with the reference OLEDs device (76.0 cd/A) using ITO as anode. 

C71.00148: Thermally induced metaltoinsulator transition in NbO_{2} thin films Toyanath Joshi, Eli Cirino, Sophie Morley, David Lederman Modification of the carrier dynamics in correlated oxide systems via epitaxial strain is a promising pathway for the practical realization of energyefficient electronic devices. Here we present on the thermally induced metaltoinsulator transition (MIT) of epitaxial NbO_{2} films grown on Al_{2}O_{3} substrates and the modulation of the MIT temperature via epitaxial strain from the substrate. The metalinsulator transition temperature increased from 910 K to 1066 K with increasing strain. An ultrathin 3.9 nm film consisting of a single strained layer with minimal structural defects yielded a bulklike sharp transition. The substrateinduced strain offers a new degree of freedom to improve device functionality of MIT materials. 

C71.00149: Synthesis and characterization of new multinary chalcogenides Masoud Mardani, Kaya Wei, Theo Siegrist Multinary chalcogenides have drawn a lot of attention due to their interesting properties. We report on newly synthesized quaternary and quintenary chalcogenide family materials. The thermal, electrical, and magnetic properties of the new materials will be discussed in detail as well as their potential technological applications. Structural results will be presented and structureproperty relationships will be discussed. 

C71.00150: Structural Design and Manufacturing of ThreeDimensional Porous Superstructures with Additive and Subtractive Electrochemistry for Flexible SelfPowered Electronics and Electromechanical Devices Weigu Li, Donglei (Emma) Fan The recent search for advanced materials with desired properties for the nextgeneration flexible energy and electronics has been focused on the unique class of threedimensional (3D) porous superstructures made of 2D materials, such as graphene, graphite, and molybdenum disulfide. 

C71.00151: Insitu Raman investigation of LaserInduced Graphene using Machine Learning Vivek Jain, Alex Tyrrell, Hud Wahab, Lars Kotthoff, Patrick A Johnson Highquality graphene was laserinduced from precursors graphene oxide and commercial polyimide. Laser annealing is a promising method to create graphenebased devices including sensors, biomedical equipment and thinfilm transistors. A Bayesian optimizationbased machinelearning strategy was used to predict optimal process parameters. We custombuilt our system to allow simultaneous laser patterning processing and insitu Raman spectroscopy characterizations. The Raman G/D ratio is a good indication of the quality of the laserinduced graphene. Rapid and significant improvements in the G/D ratios were seen with the machinelearning predicted process parameters. This experimental setup has enormous potential in Autonomous Research Systems for new materials discovery and can be scaled up for advancedmanufacturing patterned graphenebased electronics. 

C71.00152: Optical phenomena of irradiation induced molybdenum disulfide Kory Burns, Anne Marie Zhao Hui Tan, Adam Gabriel, Lin Shoa, Richard Hennig, Assel Aitkaliyeva Irradiation introduces damage cascades, destroys the periodicity of the lattice, and pushes the material away from equilibrium. In this contribution, we utilize heavy ion and gamma irradiations to alter the optical properties of twodimensional (2D) materials such as MoS_{2}. Irradiation offers a pathway to introduce desired defect densities to any given material, and, in case of lowdimensional materials, can be used to control physical properties. Defects introduced using irradiation were characterized using transmission electron microscopy (TEM) and photoluminescence (PL) measurements. We primarily focus our attention on the behavior of valley excitons, as they dominate the optical response of the material even when the system is in equilibrium and reveal the emergence of dark excitonic states in the Kvalley. With this work, we offer insight into how increased defect density can potentially engineer magnetism in 2D MoS_{2}. 

C71.00153: NonDestructive Thickness Mapping of WaferScale Hexagonal Boron Nitride Down to a Monolayer Andrea Crovetto, Patrick Whelan, Ruizhi Wang, Miriam Galbiati, Stephan Hofmann, Luca Camilli Characterization of the thickness and continuity of wide band gap 2D materials with monolayer sensitivity over large areas has proven to be very challenging. A prime example is 2D hexagonal boron nitride (hBN). Optical contrast methods suffer from the lack of visible absorption in the material; Raman spectral signatures are weak and often not conclusive; and electrical measurements are not possible due to a high electrical resistivity. In this contribution, we will demonstrate an experimental method based on the ellipsometry technique, which makes it possible to map the thickness and continuity of largearea hBN monolayers and bilayers transferred to Si/SiO_{2} substrates. The method has submonolayer thickness sensitivity, is relatively fast, nondestructive, and can be easily automated. The hBN thicknesses measured in this study have been confirmed by Raman spectroscopy, xray photoemission spectroscopy, and by a series of ellipsometry control experiments. We will present a workflow of our experimental procedure, so that other researchers can extend this characterization method to other 2D materials and hopefully accelerate their development. 

C71.00154: Raman Enhancement effect using hexagonal Boron Nitride with a substrate Jessica Lemos, Andreij de Carvalho Gadelha, Cristiano Fantini Leite, Eliel Gomes da Silva Neto The Raman enhancement effect is a phenomenon for fundamental studies of both lightmatter and mattermatter interactions and applications. Among the several Raman enhancement techniques, the surfaceenhanced Raman scattering (SERS) has been the most studied. There are two different mechanisms for SERS effect, the first one is the electromagnetic mechanism when is the local electromagnetic fields around the metallic structures can be amplified. The second is the chemical mechanism which is lower understood, and its magnitude is smaller than the electromagnetic effect. The substrate surface is very important to control the necessary enhancement to make the technique as valuable as it has become. In this work, we study hexagonal boron nitride (hBN) a twodimensional layered material with a substrate for a type of SERS, an insulator whose gap is approximately 5eV. 

C71.00155: Dual comb spectroscopy for measuring the group velocity dispersion of optical fiber realized by fast locking of the beat note with a piezoelectric module Ryosuke Tabuchi, Kana Alyssa Sumihara, Sho Okubo, Makoto Okano, Hajime Inaba, Shinichi Watanabe Dualcomb spectroscopy (DCS) emerged a decade ago as a powerful tool for gas spectroscopy and metrology. DCS is based on two optical frequency combs (OFCs) with slightly different repetition rates. Using DCS, one can simultaneously obtain amplitude and phase of the light, resulting in the direct determination of complex refractive index. Thus, DCS promises for investigating the solid state materials. 

C71.00156: Heavy Mediator at Quantum Dot/Graphene Heterojunction for Efficient Charge Carrier Transfer to Enhance the Performance of the Optoelectronic Devices RAPTI GHOSH The twodimensional mediator with heavy effective mass possesses a large density of states that can be inserted at the twodimensional heterostructure interface. In general, the 2D heterostructure interfaces suffer from enhanced depletion region which deteriorates the charge carrier transfer efficiency and hence the device performance. The insertion of the mediator reduces the depletion region and form type–II band alignment which speeds up the carrier dissociation efficiency and hence eventually enhances the carrier transfer phenomena. 

C71.00157: Nonlinear Refractive Index Measurement of Ebeam Evaporation Ta_{2}O_{5} film TEKENG WANG, ChaoHong Lin, JiaWei Liu, FuYan Yan, HanTing Hou, MinHsiung Shih, ChaoKuei Lee Tantalum pentoxide(Ta_{2}O_{5}) has been realized as a promising material for waveguide due to its great linear optical properties, such as high refractive index, large bandgap and so on. Recently, the nature of athermal property and high nonlinear refractive coefficient exhibit its potential for Si photonics application. In this work, using egun deposition growth Ta_{2}O_{5} thin film, high quality microring resonator was fabricated. The propagation loss as low as 0.3/cm was characterized from the transmission spectrum. Additionally, the nonlinear refractive coefficient (n_{2}) was investigated by using all optical modulation technique. The n_{2} of 1.42 x 10^{14} cm^{2}/W was estimated. Compared to the conventional materials for Si photonics, such as Si_{3}N_{4}, SiO_{2} and so on, the larger n_{2} value reveal the value for application. 

C71.00158: Investigation of the Resistive Switching Mechanism in Li_{x}NbO_{2} Memristors Sebastian Howard, Louis F. J. Piper, Matthew J. Wahila, Christopher Singh, WeiCheng Lee, Timothy M. McCrone, William A. Doolittle, Alex Weidenbach, Galo J. Paez A complete understanding of the origin of resistive switching in memristors is necessary for implementation into neuromorphic computing applications. However, the resistive switching of memristors is typically attributed to a complex combination of processes (e.g., redox reactions, ionic transport, phase changes, etc.) post an electroforming step, which limits tunability and scalabilitiy of the device. Li_{x}NbO_{2} analog memristors circumvent the electroforming step and demonstrate a promising new mechanism wherein the diffusion of Li^{+} ions enables precise control of the resistive states [1]. Here we utilize synchotronbased xray spectroscopy techniques to examine the electronic strucure of Li_{x}NbO_{2} memristors. We employ xray absorption spectroscopy (XAS) across the active to observe variations in the Li content. Additionally, we investigate the origin of nonvolatility by probing the buried interface at the metal contacts via hard xray photoelectron spectroscopy (HAXPES). This work opens a new avenue of methodology for illuminating resistive switching mechanisms in memristors from a fundamental perspective. 

C71.00159: Tunable Dirac points and zeroenergy modes in periodic curved graphene superlattices Jianli Luan, Shangyang Li, Tianxing Ma, LiGang Wang, HaiQing Lin We combined periodic ripples and electrostatic potentials to form curved graphene superlattices and studied the effects of spacedependent Fermi velocity induced from curvature on their electronic properties. With equal periods and symmetric potentials, the Dirac points do not move, but their locations shift under asymmetric potentials. This shift can be tuned by curvature and potentials. Tunable extra gaps in band structures can appear with unequal periods. The existence of new Dirac points is proposed, such that these new Dirac points can appear under smaller potentials with curvature, and their locations can be changed even under a fixed potential by adjusting the curvature. Our results suggest that curvature provides a new possible dimension to tune the electronic properties in graphene superlattices and a platform to more easily study physics near new Dirac points. 

C71.00160: On degradation and reliability testing GaN Highelectronmobility transistor (HEMT) Parveen Kumar Gallium nitride (GaN) based high electron mobility transistors (HEMTs) have shown a lot of promise in high voltage, high power, and high radiation applications. However, the full realization of the IIInitride potential and largescale adoption of this technology has been hindered by the existence of electrically active defects that manifest as deep levels in the energy bandgap. These deep levels can potentially act as charge trapping centers limiting device performance and longterm reliability. It is therefore imperative to monitor these traps in operational GaN HEMTs as close as possible to their realworld operational conditions. With that goal in mind, in this work, a suite of advanced thermal and opticalbased trap spectroscopy methods and models are reported and expanded upon to directly probe and track traps in threeterminal operational of GaN HEMTs. 

C71.00161: Stress/Strain Effects on Phonon Modes and Phonon Deformation Potentials in Monoclinic βGa_{2}O_{3} Rafal Korlacki, Mathias Schubert, Alyssa Mock, Sean Knight, Vanya Darakchieva Straininduced shifts of phonon energies provide a powerful tool for modeling strain patterns in heterostructures and thin films. In the case βGa_{2}O_{3}, an emerging widebandgap semiconducting oxide, the low symmetry of its monoclinic structure is responsible for the high anisotropy and unusual ordering of phonon modes, while the effects of stress and strain on the phonon properties in general are not yet well understood. We present a rigorous, symmetrybased analysis on how the frequencies of optical phonon modes depend on the components of stress and strain tensors in monoclinic crystals, and we confront it with the results of density functional theory (DFT) calculations involving several distinct deformation scenarios, and the resulting shifts in phonon mode frequencies for βGa_{2}O_{3}. We derive sets of phonon deformation potential parameters for all phonon modes, including infraredactive (A_{u} and B_{u}) and Ramanactive (A_{g} and B_{g}) modes. Additionally, we discuss how stress affects the order of phonon modes with B_{u} symmetry. 

C71.00162: Thermal and Magnetic Properties of Landau–Quantized Group VI Dichalcogenide Carriers in the Approach to the Degenerate Limit N J Horing, Jay D Mancini This work is concerned with determination of the thermal and magnetic behavior of the Group VI Dichalcogenides in a quantizing magnetic field. Our analysis treats the principal statistical thermodynamic functions (grand partition function and the ordinary partition function, as well as the grand potential, Helmholtz free energy and the entropy), providing the basis for calculation of the specific heat: Their dependencies on temperature and magnetic field strength are carefully examined, particularly in the degenerate regime and the approach to zero temperature. The joint dependence on magnetic field and temperature is also determined for the Dichalcogenide magnetic moment in the degenerate statistical regime, replete with de Haas–van Alphen oscillatory phenomenology and also above the zero–temperature limit. 

C71.00163: Effect of electric potential fluctuations in Coulomb drag in double layer graphene systems Ryan A. Bogucki, Ben Hu We study theoretically the drag transresistivity in a graphene double layer system exhibiting electric potential fluctuations. The fluctuations are modelled as sinusoidal oscillations in the first layer, which induces a sinusoidal variation in the electron density in that layer, which in turn induces an electron density oscillation in the second layer. We calculate the drag resistivity as a function of average charge densities in each layer for various amplitudes of the electric potential fluctuations. Recent experiments have found that the drag transresistivity in graphene double layers systems exhibit a sign change when one layer is held at the charge neutrality point, and the average density of the electrons in the other layer is varied through the charge neutrality point. Our simple model is able to qualitatively reproduce these experimental results. We discuss extensions of the model which characterize more realistically the electric potential fluctuations that are caused by the presence of charge density impurities near the graphene layers. 

C71.00164: Thermal expansion coefficients of high thermal conducting BAs and BP materials Sheng Li, Keith Taddei, Xiqu Wang, Hanlin Wu, Joerg C. Neuefeind, Davis Zackaria, Xiaoyuan Liu, Clarina Reloj Dela Cruz, Bing Lv Recently reported very high thermal conductivities in cubic boron arsenide (BAs) and boron phosphide (BP) crystals could potentially provide a revolutionary solution in the thermal management of high power density devices. To fully facilitate such an application, the compatible coefficient of thermal expansion (CTE) between the heat spreader and the device substrate, in order to minimize the thermal stress, needs to be considered. Here, we report our experimental CTE studies of BAs and BP in the temperature range from 100 K to 1150 K, through a combination of Xray single crystal diffraction and neutron powder diffraction. We demonstrated that the room temperature CTEs,3.6 ± 0.15*10^{6 }/K for BAs and 3.2 ± 0.2*10^{6} /K for BP, are more compatible with most of the semiconductors including Si and GaAs, in comparison with diamond, and thus could be better candidates for the future heat spreader materials in power electronic devices. 

C71.00165: OUTREACH AND ENGAGING THE PUBLIC


C71.00166: Dying Fundamental Physics and Rising Digital Era of Engineering Pritam Mandal From a study based on personal teaching experiences and onetoone and ingroup interaction with a large number of students (9^{th} to 12^{th} Grade and UG levels), teachers, research scholars and labexperts across India, we found that most of the students in the science stream no longer “view” Physics as a branch of science to study the nature, rather Physics for them is a giant toolbox to design more sophisticated devices and medicines for “social use”. To most of them, knowing physics means becoming smarter at handling electricity, electronic gadgets, computers, smartphones and apps. Most of the science students were found not driven to learn physics as a way to understanding and relishing the hidden deeper beauty of nature; for them the new wonderland is the “online” world. 

C71.00167: WITHDRAWN ABSTRACT


C71.00168: PUBLIC POLICY


C71.00169: Research Integrity, the Responsible Conduct of Research, and Plagiarism Analysis Aaron Manka Among its duties, the National Science Foundation (NSF) Office of Inspector General (OIG) is responsible for helping ensure the integrity of research programs at NSF. We investigate allegations of research misconduct (plagiarism, falsification, and fabrication) in NSF proposals and awards. We also handle allegations conflict of interests and violations of the confidentiality of NSF’s merit review to ensure the integrity of that process. We completed a review of how grantees implemented NSF’s requirement to provide responsible conduct of research training to undergraduate students, graduate students, and postdoctoral researchers. We have analyzed our plagiarism cases of the past decade to accumulate data and potentially identify institutional strategies for preventing and reducing plagiarism. We are also reviewing grants for characteristics of serial spending. I will briefly discuss these topics and present our results. 

C71.00170: ENERGY RESEARCH AND APPLICATIONS


C71.00171: Perovskite Electronic Ratchet for Energy Harvesting Ji Hao, Haipeng Lu, Jeffrey L Blackburn, Andrew Ferguson Hybrid organicinorganic perovskite semiconductors (HOIS) have demonstrated great potential as absorbers in thinfilm solar cells, but recently there is emerging research demonstrating their application as the electronic materials in transistors, diode, and optoelectronic devices due to their unique mixed ionicelectronic properties. Here we demonstrate a novel energy harvesting application based on both ionic and electronic transport in HOIS — Perovskite electronic ratchets. The electronic ratchet is a new type of energy harvesting device that can convert (rectify) a nondirectional electrical signal into stable direct current through an asymmetric potential distribution across the device (i.e., the device acts as a charge pump). Here we demonstrate the first leadhalide perovskite electronic ratchet by manipulating the ion distribution within a transistor channel to realize an asymmetric potential distribution in the perovskite device. This asymmetric potential distribution allows the perovskite ratchet device to convert both electronic noise and unbiased, periodic alternating potentials into stable direct current. Such devices have the potential for providing lowvoltage power in remote and portable applications. 

C71.00172: FerrofluidBased Generator Harvesting Waste Heat and Ambient Vibration Xuewei Zhang Ferrofluid is a stable colloidal suspension of permanently magnetized nanoparticles, in which Brownian motion keeps the nanoparticles from settling under gravity, and a surfactant is placed around each particle to provide short range steric repulsion between particles to prevent particle agglomeration. Since magnetic field device has no limitations analogous to electrical breakdown in its electric field counterpart, ferrofluids have become an excellent choice for micro/nanoelectromechanical systems technology. On the other hand, ferrofluids have applications in the cooling of electronic devices, which has led to several designs of power generators using waste heat. In this work, we study a new version of ferrofluid generators harvesting both heat and vibration energy. A theoretical model based on fundamental physics principles is developed to evaluate the system's energy conversion efficiency (the ratio of generated power and the heat input). Further, we discuss the dependence of the output power on various design parameters (including the scale of the system) and methods to enhance the performance of the ferrofluid generator for potential aerospace applications. 

C71.00173: Thermoelectric properties of Asbased 1111Zintl compounds La_{1x}Sr_{x}(Zn,Cd)AsO Yusuke Kimura, Kunihiro Kihou, Hirotaka Nishiate, Hidetomo Usui, Yuto Tokunaga, Tsutomu Iida, Kazuhiko Kuroki, ChulHo Lee 1111system with the ZrCuSiAstype structure has attracted great attention not only as the highTc superconductors but the highperformance thermoelectric compounds. The highest ZT in 1111system was found in BiCuSeO with the value of ZT to be 1.4 at 923 K [1], demonstrating the high potential of the 1111system as thermoelectric compounds. Previously, we found that LaFeAsO_{1y} exhibits large power factor with values of PF = 4.1 mW/mK^{2} at T = 75 K [2], demonstrating that Asbased 1111system can also be a candidate. 

C71.00174: Understanding pressuredriven thermoelectric properties of PdP_{2} and PdAs_{2} nanowires via band engineering Prabal Bhuyan, Yogesh Sonvane, P. N. Gajjar, Rajeev Ahuja, Sanjeev K. Gupta In the race of searching for alternative clean and sustainable energy sources, thermoelectric materials have shown potential hope by converting lowgrade waste heat into electricity. The efficiency of thermoelectric devices is characterized by power factor or ZT. Therefore, enhancing ZT in nanowires for the thermoelectric application is highly desired. In recent work, we propose semimetallic nanowire with asymmetry density of states near the Fermi energy as an alternative class of thermoelectric materials. We have considered the pentagonal structure of PdP_{2} and PdAs_{2 }nanowires (NWs) and confirmed its dynamical stability by the phonon dispersion study. The PdX_{2 }structure shows the transition from semiconducting to semimetallic behaviour at a compressive strain of 8% within sustainable pressure of 0.2~0.3GPa. The semimetallic behaviour with the asymmetric density of states near the Fermi energy boosts Seebeck coefficient value and therefore, ZT_{e} value is enhanced for both the nanowires. Our study stimulates both nanowire synthetization feasibility and thermoelectric applications for the conversion of waste heat into electricity. 

C71.00175: Optimized Efficiency of a stochastically driven quantum dot Heat Engine Mulugeta Bekele We take a stochastically driven single level quantum dot embedded between two metallic leads at 

C71.00176: Thermoelectric Properties of Solvothermal Grown Bismuth TellurideCarbon Nanomaterials Composites Daniel Choi, Karima Perry, Patrick Taylor, Evgeniya Lock, Shashi P Karna Current state of the art portable power source faces problems such as lowlife, high production cost and weight penalty. As such, thermoelectric (TE) power generation and cooling have been considered as an alternative as lowcost, more efficient, environmentally responsible approach. One of more promising TE material of interest are alloys based on bismuth telluride (Bi_{2}Te_{3}) and thus much efforts have been made to improve TE properties by (1) reducing the materials’ dimension to nanoscale, and (2) incorporating other nanostructures such as graphene, to enhance electrical properties and thermal conductivity. This geometry offers a natural architecture for thermoelectric devices due to reduced thermal transport and enhanced electronic tunneling at the nanomaterial interfaces. Building upon this mechanism, we present thermoelectric properties of Bi_{2}Te_{3} composited with various carbon nanostructures. Our TE materials are synthesized via solvothermal method resulting in uniformly dispersed nanoplates interfaced with 1D and 2D carbon nanostructures. Our results not only show change in thermoelectric properties of Bi_{2}Te_{3} upon incorporation of carbon nanostructures, but provide characterization of Bi2Te3nanomaterial interface for development of nextgen, low power, portable power source. 

C71.00177: Defects and band positions in the ptype transparent conductor CuI Andrea Crovetto, Sergiu Levcenko, Hannes Hempel, Marin Rusu, Thomas Unold While highperformance ntype transparent conductive materials (TCMs) have existed for decades, heavy ptype doping of wide bandgap materials has proven much more challenging. The simple cubic compound CuI was recently rediscovered for this application and is currently the ptype TCM with the highest figure of merit. However, the native defects responsible for ptype conductivity in CuI, as well as compensating defects limiting the maximum achievable doping levels, have not yet been identified experimentally. Furthermore, there is disagreement in the literature on the work function and absolute band positions of CuI relative to vacuum. In this experimental study, we employ temperature and intensitydependent photoluminescence to draw new conclusions on the defect landscape of CuI. We then employ a combined photoemission spectroscopyKelvin probe system to show that the measured band positions depend critically on surface phenomena. Finally, we demonstrate that terahertz spectroscopy is an ideal tool for characterizing the electrical properties of CuI reliably and nondestructively. 

C71.00178: Computational Screening and Designing Highperformance Solid Sorbents for CO_{2} Capture Technology Yuhua Duan


C71.00179: Improved optoelectronic properties in CdSe_{x}Te_{1x} through controlled composition and shortrange order Bishal Dumre, Nathan J Szymanski, Vijaya Adhikari, Indiras Khatri, Daniel Gall, Sanjay V. Khare We employ first principles methods based on density functional theory and beyond to study CdSe_{x}Te_{1x} alloys in the zincblende and wurtzite structures. From the cluster expansion formalism, we provide phase diagram showing consolute temperature of 325 K where zincblendetowurtzite phase boundary is found for Se concentrations of x = 0.50.6 owing to increasing ionic character of the Cdanion bonds. Disordered CdSe_{x}Te_{1x} configurations are modeled using special quasirandom structures, for which optoelectronic properties are computed with the hybrid HSE06 functional. Downward bowing in the band gap and effective hole mass of the zincblende structure is highlighted for its potential benefits in photovoltaics through increased net photocurrent. Absorption coefficient and reflectivity are also reported, showing promising results in zincblende CdSe_{x}Te_{1x} as indicated by substantial optical absorption throughout all Se concentrations. Lastly, we identify the presence of shortrange order in CdSe_{x}Te_{1x} characterized by clustering among like atoms in order to minimize strain. The degree of clustering, which may be tuned by temperature, also controls the magnitude of the band gap. 

C71.00180: A Multidimensional Approach to Structural Transformation Through Functionalization of Tellurene Gracie Chaney, Daniel Wines, Fatih Ersan, Jaron Kropp, Can Ataca Two dimensional (2D) Tellurene (Te) structures have recently been synthesized, and have been shown to possess high mobility and stability. Using density functional theory (DFT) and molecular dynamics (MD), we investigated the stability and electronic structure of 2D, and phase sheets, and their hydrogen, oxygen, and fluorine functionalized counterparts. Our calculations show that bare  and Te sheets are stable and have band gaps of 0.44 eV and 1.02 eV respectively. We see that H, O and F destabilize Te; F and H cause Te layers to separate into functionalized atomic chains; and O causes Te to totally transform into a Te_{3}O_{2}like structure. Also, we studied the coverage effects of different concentrations of H and O on and βTe and found that the full coverage case results in the highest binding energy and stability for both adatoms. Finally, we examined the stability and binding nature of functionalized βTe on a GaSe substrate. We noted that having O and H impurities not only enhances the stability of Te layer, but also results in a strong binding energy on GaSe substrate. Our results indicate that Tellurene monolayers and functionalized counterparts are suitable for future optoelectronic devices and as metallic contacts in nanoscale junctions. 

C71.00181: Investigation of Au(111)/Li_{3}PO_{4} Interface Structures using Neural Network Potential Koji Shimizu, Wei Liu, Wenwen Li, Yasunobu Ando, Emi Minamitani, Satoshi Watanabe Recently, the construction of interatomic potentials using firstprinciples calculation data and machinelearning technique has been widely tried because of higher reliability and low computational costs. In the present study, we have tried to construct the fourelement neural network potential (NNP) [1,2] to investigate the Au(111)/Li_{3}PO_{4} interface system, where the understanding of the interface structures and Liion distribution near the interface is of significance for the development of allsolid state Liion batteries and novel memory devices [3]. Using the constructed NNP, we then performed structure optimization with a large interface model of Au(111)/Li_{3}PO_{4}. In the meeting, we will discuss the calculated interface structures and the Li defect formation energies. 

C71.00182: Strong interplay between Na and Orelated defects in Cubased chalcogenides Kostiantyn Sopiha, Sigbjørn Grini, Charlotte PlatzerBjörkman, Lasse Vines, Clas Persson Recent advances in thinfilm photovoltaics became possible by controlling the incorporation of impurities. The most notable among them are alkalis indiffusing from sodalime glass and oxygen incorporating from various sources during the baseline processing. Herein, we investigate the interaction between Na and O in cosputtered Cu_{2}ZnSnS_{4}(CZTS) by combining theoretical and experimental techniques. First, using secondary ion mass spectrometry (SIMS), we demonstrate that Na and O distributions in the absorber are correlated. Then, employing firstprinciples methods, we show that the correlation is driven by a strong ionic NaO bonding that triggers the formation of NaO and Na_{2}O complexes. The remarkably high binding energies for these complexes are proven to cause NaO clustering at all temperatures of the baseline processing. Hence, the overall character of the impurity profiles is explained through O immobilizing Na by forming the defect complexes and leading to the Na accumulation near the CZTS surface. This defect interplay paves the way for a more accurate impurity control needed for fabricating highperformance devices. 

C71.00183: Energetic and vibrational properties of carbon monoxide adsorption on platinum nanoparticles under applied voltage Cierra Chandler, Ismaila Dabo Carbon monoxide poisoning is a significant limitation to the performance of platinumbased transition metals. Manipulating the size of the catalytic particles could help inhibit carbon monoxide adsorption and increase the life cycle of the catalyst. This study models the energetic and vibrational properties of carbon monoxide on platinum nanoparticles under applied voltage using the selfconsistent continuum solvation (SCCS) model. We determine adsorption patterns as the function of nanoparticle size and site coordination. It is found that the local surface charge strongly affects carbon monoxide adsorption particularly along the (111) and (001) facets of the nanoparticle. These results could prove useful in optimizing electrocatalytic systems such as proton exchange membrane (PEM) fuel cells where trace amounts of carbon monoxide in the hydrogen fuel can poison the nanostructured platinum electrodes and decrease the durability of the fuel cell. 

C71.00184: Evanescent field polarization for giant chiroptical modulation from achiral gold halfrings: Theoretical insight from simulations Luca Bursi, Lauren A. McCarthy, Kyle W. Smith, Alessandro Alabastri, Peter J. Nordlander, Stephan Link Metal nanoantennas have been under intense investigation due to their strong light−matter interactions and significant polarization sensitivities determined by their nanostructure. For applications seeking to realize onchip polarizationdiscriminating nanoantennas, efficient energy conversion from surface waves to farfield radiation is desirable. However, the response of individual nanoantennas to the particular polarization states achievable in surface waves, such as evanescent fields, has not yet been thoroughly studied. 

C71.00185: WITHDRAWN ABSTRACT


C71.00186: Free Energy Landscape of Sodium Solvation into Graphite Ali Kachmar, William Andrew Goddard Sodium Ion Batteries (SIBs) are the most costeffective alternative to current generation lithium ion batteries (LIBs), ^{[1,2]} but Na is known to deliver very low energy capacity for sodium intercalation compared to Lithium. We report here first principles moleculars dynamics aided by metadynamics ^{[3]} to obtain the free energy landscape including changes in the electronic coupling as a sodium ion in Dimethyl sulfoxide solvent intercalates into graphite, the first step in understanding how the local environment affects the free energy of solvation. We analyze the free energy landscape for all the possible sodium solvation scenarios, while quantifying their free energy barriers. Our simulations indicate that solvent plays an important role in stabilizing the sodium intercalation into graphite through shielding of the sodium while modulating the interaction of the solvent with the graphite sheets ^{[4]}. 

C71.00187: Catalytic growth of Ndoped MultiLayer Graphene/Carbon Composites for Supercapacitor Applications Ayush Bhardwaj, Alexander Ribbe, James J Watkins Multilayer graphene (MLG) composites are excellent candidates for supercapacitor applications, but current approaches to device fabrication and the cost to produce graphene poses challenges for commercialization. Here, we use iron nitrate nonahydrate as a catalyst for the growth of graphene, melamine formaldehyde resin as a solid carbon source, and Pluronic F127 surfactant as a sacrificial porogen to enhance porosity and surface area. The MLG composites are produced via thermal carbonization. The resulting composites exhibit high surface area (2200 m^{2}/g) and significant nitrogen doping (45%), yielding specific capacitance values as high as 300 F/g at 0.5 A/g. The role of temperature and coordination between functional group of the carbon precursor & metal source has been investigated to understand MLG formation. 

C71.00188: Determination of the Enthalpy of Adsorption of Hydrogen in Activated Carbon at Room Temperature Ernest Knight, Andrew K Gillespie, Matthew Johnson Prosniewski, David Stalla, Elmar Dohnke, Tyler Rash, Peter Pfeifer, Carlos Wexler A very important quantity for adsorption performance is the enthalpy of adsorption ΔH. The determination of ΔH for weakly adsorbing gases (e.g., H_{2}) in carbonaceous porous materials is difficult, normally requiring measuring adsorption isotherms at two cryogenic temperatures and calculation of ΔH using ClausiusClapeyron’s (CC) equation. Here we demonstrate a calculation of ΔH based on ca. room temperature isotherms at 273K, 296K. CC requires absolute isotherms; however, excess adsorption is measured; conversion between these requires the adsorbed film volume. We show that the film volume can be estimated by fitting the excess adsorption with an OnoKondo model and the auxiliary use of a fixed point corresponding to the saturation film density (estimated 100±20 g/L) which seems to be remarkably sample and temperatureindependent, i.e., an adsorbate property. We find that for highquality porous carbons the film volumes are ~40%, ~12% of the total pore volume at 77K, 296K, respectively. Using these, we calculate ΔH = 8.3±0.4 kJ/mol at room temperature, an excellent agreement with the lowcoverage cryogenic determination. The methodology proposed facilitates reliable calculations of the ΔH at room temperatures for weaklyadsorbing gases. 

C71.00189: Thermal conductivity of hydrogen sorbent materials for onboard storage applications Noemi Leick, Robert Bell, Troy Allen Semelsberger, Brandon Barnett, Jeffrey R Long, Philip Anthony Parilla, Thomas Gennett Measuring the thermal conductivity (TC) of H_{2}physisorption storage materials under system conditions are critical in designing the most practical onboard H_{2 }storage vessels. Furthermore, knowing the TC helps understanding how the heat associated with the sorption/desorption of H_{2 }is distributed throughout the storage material. 

C71.00190: Thermal and Spectroscopic (IR, NMR) Studies of Ammonia BoranePolyethylene Oxide Hydrogen Storage Composites: Effect of Catalyst Ozge GunaydinSen, Krishna Kharel, Emily Ingram, Caitlyn Clark, Riqiang Fu Ammonia Borane (NH_{3}BH_{3}, AB) has been a potential candidate for chemical hydrogen storage due to its high hydrogen content (19.6 wt%). A downfall to the applicability of AB is its slow dehydrogenation kinetics and production of unwanted byproducts/gases. Studies show that introduction of a polymer, such as polyvinylpyrrolidone and polyacrylamide, can improve the performance of AB and decrease the release of harmful byproducts. Furthermore, catalytic additions such as, magnesium chloride (MgCl_{2}) and calcium chloride (CaCl_{2}), have proven to lower the activation energy (E_{a}), improve kinetics, and lower the hydrogen release temperature. This study explores thermal and vibrational analysis of pristine AB blended with polyethylene oxide (PEO) and individual additions of MgCl_{2} and CaCl_{2} as catalysts. Dehydrogenation kinetics were studied using a differential scanning calorimeter and the data was then compared with AB, bulk composites and analyzed. The results with CaCl_{2} catalyst and high PEO content exhibited the most improved properties (i.e. lower E_{a}). In addition, evidence of the interactions between AB:PEO:Catalyst were given by Fouriertransform infrared and nuclear magnetic resonance spectroscopy. 

C71.00191: The Impacts of Synthesis Routes and PhasePurity on WaterSplitting Behavior in the BariumCeriumManganese System Dan Plattenberger, Robert Bell, Sarah Shulda, Nicholas Strange, Philip Anthony Parilla, Anthony McDaniel, Michael Toney, David S Ginley Solar thermochemical hydrogen production (STCH) is a promising technology for solar fuels with high theoretical solarthermal watersplitting efficiency. However, many candidate STCH oxides are complex ternary oxides, and they have the potential for secondary phase formation during synthesis and subsequent redox cycling. During synthesis, pervasive refractory impurity phases can occur, which impede the ability to develop a basic understanding of the STCH potential and complicate structural refinement of chemical expansion during isothermal reduction/oxidation. This work focuses on high phasepurity synthetic routes for known watersplitting oxides; in particular, BaCe_{0.25}Mn_{0.75}O_{3} (BCM). These are approached by synthesizing both bulk ceramic and thin films, which are analyzed via inoperando synchrotronbased Xray diffraction (XRD) to provide the highest quality structural refinements on BCM and other complex STCH oxides to date. The relationship between chemical shift and oxygen vacancy concentration is determined using a combination of flowcell measurements and inoperando XRD during isothermal reduction and oxidation. In addition, key data for training computational simulations of vacancy formation and the effect of vacancies on structures is presented. 

C71.00192: Frustrated Lewis Pairs with Applications in Hydrogen Storage Glory RussellParks, Brian Trewyn, Thomas Gennett Due to the abundance and large gravimetric energy density, hydrogen has been considered a potential source of energy.^{1 }Major challenges with utilizing hydrogen for energy include efficient and safe storage and transportation of it. Frustrated Lewis pairs (FLPs) have recently proven their importance in hydrogen storage.^{2} In contrast to commonly known Lewis acidbase pairs, functionalizing the acid and base with bulky groups prevents them from binding to their counterpart causing them to be “frustrated”.^{3} The acid and base are held together by weak intermolecular forces without neutralization, which allows small molecules such as hydrogen to weakly bond to the Lewis acid and base in a heterolytic mechanism. FLPs as catalysts have unique characteristics including a wide range of compatible donors and acceptors.^{2} These attributes may assist with lowering the sorption temperature and pressure, reducing the activation energy barrier and potentially allowing for hydrogenation and dehydrogenation to occur. This work focuses on the novel synthesis and characterization of an FLP system. 

C71.00193: Improving Cyclability of Metal Borohydrides for Hydrogen Storage via NonMetallic Borohydride Additives. Robert Bell, Nicholas Strange, Noemi Leick, Michael Toney, Thomas Autrey, Thomas Gennett The theoretical ~15 wt% hydrogen content of magnesium borohydride is inaccessible for cyclical desorption/hydrogenation cycles at reasonable temperatures (<300°C) and pressures (<350 bar). However, a variety of additive compounds lower the Mg(BH_{4})_{2} hydrogen evolution temperature, changing the end state when hydrogen is released, and lowering the melting point of the system. These additives have included other metal borohydrides, metal hydrides, and organics (ether/glyme). Despite many of these additives lowering the liquidus temperature, desirable due to better mixing and higher theoretical kinetics in the melt, these systems often resulted in undesirable matrices upon recooling and cease to thermally cycle as expected. This work investigated an alternative family of additives, nonmetallic borohydrides; a broad class of low melting point borohydrides. The temperature and hydrogenevolution dependent phase diagram of these magnesium borohydride and nonmetallic borohydride systems was investigated via calorimetry and insitu diffraction analysis. Results of heat flow and temperature programmed desorption measurements demonstrate the improved thermal cyclability of these systems. The effect of nonmetallic cation size on the behavior of these systems will be discussed in detail. 

C71.00194: Tailoring cations in a perovskite cathode for protonconducting solid oxide fuel cells with high performance Marco Fronzi, Xi Xu, Lei Bi, Enrico Traversa A rational design of a highperformance cathode for protonconducting solid oxide fuel cells (SOFCs) is proposed in this study with the aim of improving the hydration properties of conventional perovskite cathode materials, thus leading to the development of new materials with enhanced proton migration. Herein, potassium is used to dope traditional Ba_{0.5}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3δ} (BSCF), which is demonstrated to be a beneficial way for improving hydration, both experimentally and theoretically. The theoretical study was needed to overcome practical limits that hindered direct hydrogen mobility measurements. The novel material Ba_{0.4}K_{0.1}Sr_{0.5}Co_{0.8}Fe_{0.2}O_{3} d (BKSCF) shows a lower overall proton migration energy compared with that of the sample without K, suggesting that Kdoping enhances proton conduction, which shows an improved performance by extending the catalytic sites to the whole cathode area. As a result, a fuel cell built with the novel BKSCF cathode shows an encouraging fuel cell performance of 441 and 1275 mW cm^{2} at 600 and 700 C^{o}, respectively, which is significantly higher than that of the cell using the pristine BSCF cathode. This study provides a new and rational way to design a perovskite cathode for protonconducting SOFCs with high performance. 

C71.00195: Solidstate NMR Studies of NonFullerene AcceptorBased Organic Photovoltaic Active Layers Yao Wu, Weiguo Hu, Thomas Russell The efficiency of organic photovoltaics has undergone remarkable increases in power conversion efficiencies (PCEs) recently achieving values in excess of 17% due, primarily, to the advent of nonfullerene acceptors (NFAs). To further increase PCEs, understanding and manipulating the morphology over broad range of length scales is necessary. The similarity in the chemical composition of the donors and NFAs limit current methods based on electron densities or refractive indices in discerning details of the morphology. To fill this gap we have used solidstate NMR (ssNMR) where donor and acceptor nuclei have distinct relaxation times that can be used to characterize the crystallinity, crystal size and state of mixing. Here, we present results on several donors and NFA combination where characteristics of the morphology were obtained. Donor and NFA blend film and their pristine films were studied by ssNMR. For PTB7:ITIC, the crystalline forms of ITIC show sensitive dependence on processing conditions. Furthermore, T_{1} and T_{1ρ} relaxation times were used to elucidate the phase separation behavior. For PM6:Y6, spin diffusion experiments based on the contrast between the T_{1ρ} relaxation times of PM6 and Y6 are able to detect phase separation at a length scale of <15 nm. 

C71.00196: Singlejunction and Tandem Cu_{2}BaSnS_{4} Solar Cells with a TaS_{2} hole contact Andrea Crovetto, Rasmus Nielsen, Alireza Hajijafarassar, Ole Hansen, Brian Seger, Ib Chorkendorff, Peter Vesborg Solar cells based on the wide bandgap Cu_{2}BaSnS_{4} (CBTS) absorber have achieved open circuit voltages up to 1.1 V over a short development period, making CBTS an attractive material for tandem photovoltaic and photoelectrochemical cells. In this work, we explore an alternative CBTS growth route based on sulfurization of reactively sputtered oxide precursors, and we propose TaS_{2} as an alternative back contact material. Compared to direct deposition of CBTS films from ceramic targets, reactive sputtering of oxide precursors can ultimately achieve a higher throughput and a lower cost, with the additional advantage that sulfur contamination of vacuum systems is avoided. The TaS_{2} compound is selected as a prospective holeselective contact due to its high work function and its metallic conductivity, which could prevent the losses associated with carrier transport across the semiconducting MoS_{2} layer. By comparing CBTS solar cells with Mo and TaS_{2} back contacts, the latter shows a significantly lower series resistance, resulting in a 10% relative efficiency improvement. Finally, we fabricate a proofofconcept monolithic CBTS/Si tandem cell using a thin Ti(O,N) interlayer intended both as a diffusion barrier and as a recombination layer between the two subcells. 

C71.00197: INSTRUMENTATION AND MEASUREMENT SCIENCE


C71.00198: Development of a Surface Forces Apparatus Featuring Ultrafast Nonresonant Imaging for Measuring Contact Electrification Matthew Lippy, Alexander W Bataller The charging of surfaces via physical contact, known as contact electrification, is an offequilibrium phenomenon that spans many lengthscales and can exhibit extreme energy focusing by conversion of diffuse mechanical energy into high energy xrays. Due to the challenges of performing insitu measurements of charge separation from buried interfaces, the fundamental mechanisms of contact electrification are still unknown. To make experimental advances in this field, we have developed a new multimodal platform that combines the angstrom precision of a surface forces apparatus with the interfacial access provided by a nonlinear optical measurement, i.e., second harmonic generation. Details of the instrument’s design and operation will be presented, which will include preliminary experimental results that tests how contact electrification is affected by monolayerlevels of surface absorbents. 

C71.00199: Revealing signitures of topologically protected surface states with STM AnPing Li Owing to their bulk band topology, 3D topological insulators possess a massless Dirac dispersion with spin–momentum locking at the surface. The onset of a spontaneous magnetization or a broken timereversal symmetry leads to the formation of an exchange gap in the Dirac band dispersion. In this work, we will present two salient examples to show that STM spectroscopy can be used to detect these signatures of topological surface states. The first is to measure spin–momentumlocked conduction on topological insulator Bi_{2}Te_{2}Se. A multiprobe STM with spinpolarized tips allows us to perform in situ transport measurement to differentiate surface conductance from the bulk and spinup chemical potential from the spindown. As a result, a spinmomentumlocked current is revealed which shows ultrahigh mobility and polarization. The second is to detect topologically nontrivial magnetic states in MnBi_{2}Te_{4}. Quasiparticle interference patterns are used to probe local dispersions of both surface and bulk electronic structures. The theoretically predicted gaped surface states are evaluated with high spatial resolution. It is expected that tuning of the Fermi level in the exchange gap will result in the emergence of a quantum anomalous Hall effect. 

C71.00200: Neutron Scattering at Missouri: Current Status and Future Prospects Helmut Kaiser, Thomas Heitmann, Joseph Schaeperkoetter, Paul Miceli The University of Missouri has been operating a nuclear research reactor for more than 50 years and thus has a long history in neutron scattering research. Currently, we have four neutron scattering instruments in service: a tripleaxis spectrometer (TRIAX), an unpolarized neutron reflectometer (GANS), and two doubleaxis diffractometers (2XC and PSD). We will give an overview of the performance of the instruments and of the ongoing research projects. The PSD powder diffractometer has recently been upgraded with new electronics and software and with an expansion from 5 to 15 linear position sensitive He3 detector tubes. We will illustrate the vast improvement of signalto background ratio and highlight ongoing research projects. Future plans to expand our suite of neutron instruments include a thermal neutron beam imaging station. We present a conceptual design and Monte Carlo calculations. The science case concerning Plant Imaging and Tomography will be discussed. 

C71.00201: A robust software interface for a green astrocomb: remote control and automation Willa Dworschack, Aakash Ravi, David Phillips, Ronald Walsworth Using the Doppler effect to search for exoplanets is a powerful technique. Stateoftheart spectrographs such as HARPSN at the Italian National Telescope are the workhorse tools in such searches. Though their stability is excellent, it isn’t sufficient to detect Earthlike planets around Sunlike stars due to the extremely small Doppler shifts associated with such systems (~100 kHz shifts of optical transitions). A visible wavelength, broadband 16 GHz laser frequency comb (astrocomb) can precisely calibrate spectra to resolve these Doppler shifts, but operation of this instrument requires maintenance and laser expertise. Here, we report on the successful development and implementation of a LabVIEW program that remotely operates an astrocomb and has automation features, relieving the need for onsite scientists at the Italian National Telescope on the Canary Islands and making this tool accessible to a larger community of researchers. 

C71.00202: The Structure of Degassed WaterEnabled OilinWater Microemulsions Kyle Williams, Jose L Banuelos Most anticancer agents are hydrophobic and their use on patients often requires an oil & drug delivery vehicle. The drug delivery vehicle tends to be the primary cause of side effects in patients. Growing evidence suggests that it may be possible to mix oil in water at higher concentrations if dissolved gases are removed from water. Understanding the structure of oil/water microemulsions could shed light on mechanisms of mixing. This project uses smallangle xray scattering, dynamic light scattering, and turbidity measurements to assess the structure of hydrophobic molecules mixed with degassed water. Results of nanostructure as a function of alkane molecule chain length and concentration will be presented. These results will be compared to the same measurements of biocompatible fatty acids. Determining the properties that enable their miscibility with an aqueous environment will be helpful for future drug delivery. 

C71.00203: Increasing the Nanoparticle Size Detection Sensitivity of Dynamic Light Scattering using Wavelength Dependent Excitation Daniel Guzman, Hristo V Ivanov, Bryan M Augstein, Jeffrey Simpson We report on the development of homebuilt Dynamic Light Scattering (DLS) instrumentation to measure the size of monodisperse (MD), spherical nanoparticles (NPs) of gold. HeNe and Arion lasers constitute the excitation sources for the scattering experiment, while an avalanche photodiode detects the scattered light, and an autocorrelation card analyzes the resulting signal to provide a measurement of the translational diffusion coefficient, which allows for the determination of NP diameter. We characterized our instrumentation using commerciallyproduced gold NPs with diameters ranging from 10nm to 200nm in aqueous solution. The strong wavelength λ dependence of the scattered light intensity (1/λ^{4}) provides increased sensitivity for smaller excitation wavelengths. We present DLS measurements on gold NPs using excitation from both a HeNe laser (λ = 632.8nm) and a tunable Argon laser (457nm < λ < 515nm). The increased scattering from the shorter wavelengths should increase our sensitivity to smaller particles. 

C71.00204: Application of edge detection techniques to ARPES data Luis Persaud, Christopher Sims, Gyanendra Dhakal, Firoza Kabir, Md Mofazzel Hosen, Yangyang Liu, Sabin Regmi, Klauss Dimitri, Madhab Neupane Edge detection and similar image analysis techniques are commonly used in computer vision but have not been fully realized for the purpose of ARPES data analysis. Without applying any Image analysis, the interpretation of ARPES data is left to the eyes of researchers and can be tricky and unreliable due to many sources of noise and distortion from the experimental processes, as a result, some of the finer, defining, details required to classify a material can be missed. By applying edge detection techniques, we are able to highlight key features such as distinct, clustered bands and other fine details that may otherwise have been obscured by noise and other experimental artefacts. Here we show the implementations of various image processing techniques applied to ARPES data and how they not only aid the interpretation of results, but can also be looked upon as stepping stones for better data processing techniques and potential automation of the classification of quantum materials through ARPES. 

C71.00205: Constructing New Patterns for Structured Illumination Microscopy Chi Ming Kan Ernst Abbe derived his famous formula of diffraction limit in 1873. The implication of this formula is that resolution of light microscopy is limited, which is in the magnitude of half of the wavelength of the light used in microscope. With the advancement in information theory and fluorescence techniques, going beyond theoretical limit stated by Abbe became possible. These methods are known as ‘superresolution microscopy’ and one of them is structured illumination microscopy(SIM). 

C71.00206: Focused Ion Beam Pt for Cryogenic Resistive Thermometry Portia Allen, Kirsten Blagg, Meenakshi Singh Local temperature measurements at cryogenic temperatures are important for studying thermal effects, both classical and quantum, in nanoscale devices. Resistive thermometry is a relatively simple way to obtain these measurements. However, most metals’ electron transport saturates at low temperatures, leading to constant resistances and making them ineffective for cryogenic thermometry. An exploration of Pt thermometers, deposited using a focused ion beam (FIB) system, reveals that they are very effective for low temperature thermometry. This is believed to be because of the carbon contamination of the Pt. A detailed analysis of the dependence of composition of the contaminants on deposition parameters and its effect on thermometer performance is presented here. Through this research, it is clear that FIB Pt offers a tunable, sensitive, templatefree thermometer for nanoscale, cryogenic thermometry. 

C71.00207: MEDICAL PHYSICS


C71.00208: Aggregation Dynamics of Blood Platelets Suresh Ahuja Platelet aggregation at sites of vascular injury is necessary for hemostasis and arterial thrombosis and occurs via platelet–platelet adhesion, tethering and rolling on the injured endothelium, a critical initial step in blood clot formation. In straight vessels, the presence of erythrocytes, red blood cells (RBCs) is known to push platelets toward walls, which may affect platelet aggregation and thrombus formation. 

C71.00209: A Novel EnergyResolved XRay Semiconductor Detector Tengfei Yan, Xiaodong Cui, Chunlei Yang The hyperspectral Xray imaging has long been sought in various fields from material analysis to medical diagnosis. Here we propose a new semiconductor detector structure to realize energyresolved imaging at potentially low cost. The device is designed based on the strong energydependent absorption of Xray in solids. Namely, depending on the energy, Xray photons experience dramatically different attenuation. An array or matrix of semiconductor cells is used to map the Xray intensity along its trajectory. With known Xray attenuation coefficient, the Xray spectrum could be extracted from a Laplace like transform or a supervised machine learning. We conceptually demonstrated an energyresolved Xray detection with a regular silicon camera. 

C71.00210: Improved Sensitivity of a SingleSided Magnetic Particle Imaging Scanner Jason Pagan, Amanuel Negash, Juehao Lin, Alexey Tonyushkin Magnetic Particle Imagining (MPI) is the new frontier of medical imaging, capable of imaging the distribution of superparamagnetic nanoparticles (SPIOs) in an expeditious and sensitive manner. For instance, the accumulation of SPIOs in tumor tissue, serving as tumor markers, presents the MPI device as a practical means of imaging for in vivo cancer imaging. The singlesided design is beneficial for this application allowing imaging of larger subjects. In our design of a scanner we utilize a fieldfree line (FFL) geometry of the magnetic field zero, which has a potential advantage of an increased sensitivity over the traditional approach with fieldfree point (FFP). Our prototype device uses a single primary coil to generate a magnetic excitation field. The SPIOs response to the excitation is detected by a planar receive coil on the surface of the device. Due to a singlesided geometry, differentiating a small signal on a strong excitation background becomes a challenging task and further impinges the potential sensitivity gain, thus a new planar gradiometer coil configuration was developed. Results from the numerical simulations and experimental data imply the improved sensitivity of the device over the single coil design. 

C71.00211: Retrospective quantitative harmonization in PET using deconvolution and optimal filtering Mauro Namías, Daniel Huff, Amy J Weisman, Tyler J Bradshaw, Robert Jeraj The reliability of longitudinal quantitative PET image analysis suffers if scans are acquired on different PET scanners. Here, we describe a postreconstruction harmonization method that can be implemented to enable quantitative PET analysis across scanners. 

C71.00212: WITHDRAWN ABSTRACT


C71.00213: Magnetic Resonance Imaging Thermography with Uniform Gd Microstructures Jason Nobles, Kevin Smiley, Sara Goldman, John Stroud, Karl Stupic, Zbigniew J Celinski, Janusz Hankiewicz Magnetic resonance imaging is an important technique in imaging living tissue and composite structures. Many medical procedures now use MRI as a critical component including MRI guided thermal ablation therapy used to treat cancer. Such procedures require realtime, spatially and thermally accurate temperature maps. We demonstrate an MRI temperature contrast agent consisting of uniform gadolinium microstructures dispersed within a media. We report on the performance of 6 micron wide, diskshaped Gd microstructures passivated by a layer of chromium. A SQUID magnetometer was used to determine the mass magnetization of these disks. The temperature dependence of the mass magnetization was then correlated to the nuclear magnetic resonance linewidth broadening of water protons in the presence of Gd disks. We used this correlation to demonstrate the MRI image brightness of the Gd microstructures suspended in a tissuemimicking phantom can be related to the temperature of the sample indicating these Gd disks are a good candidate for use as an MRI temperature contrast agent. 

C71.00214: Simple physical modeling for comparing respirator breathing resistance standards Dana Rottach, Susan Xu, Caitlin McClain, William King Air purifying respirators are designed to reduce the number of hazardous particles respired by wearers. One barrier to respirator use is their inherent increase in breathing difficulty. The National Institute for Occupational Safety and Health (NIOSH) evaluates respirators using Standard Test Procedures (STP) for various factors, including measuring the breathing resistance as the pressure drop across the filter at a certain relatively high flow rate. The International Standards Organization (ISO) has a competing standard based on a ‘Work of Breathing’ (WOB) concept, which considers PressureVolume (PV) work for a series of sinusoidal simulated breaths with frequencies and magnitudes reflecting a variety of occupational scenarios, from resting to intense physical exertion. We compare the WOB and NIOSH breathing resistance limits using a simple linear model, which reflects the most common type of particulate filtering respirators. We find that the NIOSH result is more stringent than the ISO standard for most of the ISO work rates, Resting, W1, W2, and W4, but is less stringent for the moderately high W3 work rate. The effect of the nonlinear flow characteristics associated with exhalation valves will be discussed along with the results of a less rigorous treatment. 

C71.00215: Deflector Cavity Design for Rapid 2D Proton Beam Scanning Emma Snively, Xueying Lu, Emilio Nanni, Zenghai Li, Valery Dolgashev, Gordon Bowden, Ann V. Sy, Sami Tantawi We investigate the design of a 2.856 GHz deflecting cavity to provide rapid 2D beam scanning for hadron therapy. We consider geometries for both conventional TM_{11} modes and TE_{11}–like modes. Designs are optimized for the case of subrelativistic protons with 150 MeV kinetic energy using simulations in HFSS to characterize the full 3D field profile. We discuss the challenge of maximizing the transverse shunt impedance while mitigating variations in the transverse voltage as a function of distance from the nominal beam axis. These changes in the effective transverse kick can lead to significant beam profile aberrations for nonrelativistic particles. 

C71.00216: Comparative Pharmacokinetics, Biodistribution and Dosimetry of ^{212}Pb labeled Antibody vs Peptide vs Small Molecule Nader Moshiri, George Sgouros, Theodora Leventouri We study the impact of carrier molecules in biodistribution and absorbed dose in normal tissue and tumors using ^{212}Pb radionuclide. ^{212}Pb (T_{1/2} =10.64 hrs) decays to ^{212}Bi (T_{1/2} = 60.6 mins) via β emission then finally stable ^{208}Pb via α and γ decays. The effective T_{1/2} could vary a lot depending on the carrier molecule. In this study, rats and mice data of ^{131}I, ^{166}Ho, ^{153}Sm and ^{177}Lu labeled DOTATATE, ^{111}In and ^{212}Pb labelled trastuzumab and ^{188}ReHEDP were utilized and fitted via SAAM II software. To calculate absorbed doses, the AUC of each organ was multiplied by the S values provided in MIRD scheme. RBE value of 5 was used to take into account the biological effect of the doses. 

C71.00217: Rotation and reflectionencompassing multispectral nonlocal means denoising filter for magnetic resonance imaging Mustapha Bouhrara, Nikkita Khattar, Richard Spencer


C71.00218: QUANTUM INFORMATION


C71.00219: Deterministic single photon subtraction for engineering exotic nonclassical states of light Supratik Sarkar, Jinjin Du, Michal Bajcsy We present an analytical and numerical simulation study of deterministic single photon subtraction using Single Photon Raman Interaction (SPRINT) [1] in a three level Λtype quantum emitter coupled with a chiral waveguide or cavity. This process of deterministic single photon subtraction is fundamentally different from the usual probabilistic single photon subtraction, which is inherently just the application of the annihilation operator on the incoming light field. Unlike probabilistic single photon subtraction, the photon subtraction probability relying on SPRINT is independent of the number of photons in the input field. We investigate the effects of the repeated application of the deterministic subtraction operator on photonic fields and the resulting changes in phase space statistics that lead to exotic nonclassical states of light, such as states with negative Wigner functions and squeezed states. We also discuss the prospects of experimental implementation of this approach. 

C71.00220: Using Trapped Ion Chains for Realization of Quantum Error Correction Daiwei Zhu, Laird Egan, Michael L Goldman, Marko Cetina, Crystal Noel, Andrew Reisinger, Debopriyo Biswas, Christopher Roy Monroe


C71.00221: Exploration of the Circularly Polarized Attosecond Pulse Generation Mechanisms by Polarization Gating ChonTeng Belmiro Chu, XiaoMin Tong, ShihI Chu We perform a fully ab initio investigation of the generation of circularly polarized attosecond pulse of atomic H driven by polarization gating. The timedependent Schrödinger equation is solved accurately and efficiently by means of the timedependent generalized pseudospectral method. We investigate the physical mechanism of this process by solving the timedependent Schrödinger equation in the integral form. In this way, the contribution of the wave function from different time segment to the induced dipole can be analyzed. The dynamic behavior during this process can be unveiled by the Bohmian trajectories of the dominant part of the wave function. 

C71.00222: High resolution AC magnetometry NMR spectrometer development using diamond nitrogenvacancy centers Zhipan Wang, William Casey, Nicholas Curro Nitrogenvacancy (NV) quantum defects in diamond are sensitive detectors of magnetic fields. Due to their atomic size and optical readout capability, they have been used for magnetic resonance spectroscopy of exceptionally low volume samples on diamond surfaces. Here we present our approaches to develop and construct a simple, lowcost NVdectected NMR spectrometer. The underlying theory and preliminary experimental data will be presented. 

C71.00223: Microwave to Optical Transducer with Single Emitters Vinodh Raj Rajagopal Muthu, Wenfang Li, Jinjin Du, Rubayet Al Maruf, Pritam Priyadarsi, Michal Bajcsy In this project, we aim to develop a quantum interface between microwave and optical photons. This is an essential component in realizing a hybrid quantum network where information needs to be interfaced between superconducting microwave circuits, which provide quantum information processing, and optical photons, which are suitable for longdistance communication. Our work investigates the potential of microfabricated devices with integrated optical and microwave cavities that use individual threelevel solidstate emitters, such as NV centres, for the efficient conversion between the microwave and optical regimes. We present analytical and numerical simulation results that explore the required characteristics of the microwave and optical cavities to achieve high conversion efficiency between the microwave and optical regimes. 

C71.00224: Growth and characterization of Si/SiGe heterostructures towards scalable qubit architecture Cedric Corley, Yuji Yamamoto, Markus Andreas Schubert, Florian Bärwolf, Marvin Zöllner, Inga Seidler, Malte Neul, Lars Schreiber, Giovanni Capellini, Wolfgang Matthias Klesse Strained Si/SiGe Quantum Well (QW) structures are a promising material system for the realization of spin qubits based on spatially confined electrons. A major advantage for Sibased structures is their compatibility with mature SiCMOS technology, providing high scalability. In this study we show a first step towards determining the relationship between the material properties (e.g. interface roughness and defect density) and qubit performance of these structures. In order to discuss the influence of the material properties of the QW, tensile strained Si QW embedded in Si_{0.7} Ge_{0.3} layers with different types of SiGe buffer layers are fabricated on 200 mm Si substrates. The material properties are characterized by various methods (XRay Diffraction, Secondary Ion Mass Spectrometry, Scanning Transmission Electron Microscopy). 

C71.00225: WITHDRAWN ABSTRACT


C71.00226: Electric manipulation of a valley qubit in a silicon quantum dot Peihao Huang In a silicon quantum dot, the valley states can be encoded as a qubit for quantum information processing. Here, we study theoretically the electric manipulation of valley qubit in a silicon quantum dot. The valley qubit frequency and electric manipulation speed are studied as a function of the location of interface steps and the applied electric field. We find that the applied electric field or the interface state can enhance the electric manipulation of the valley qubit. We further study the combined effect of QD confinement and interface steps on the electric manipulation of valley qubit. We will discuss the consequence of the results on the valley qubit based quantum information processing. 

C71.00227: A Platform for LightHole Qubits in Group IV Semiconductors Patrick Del Vecchio, Anis Attiaoui, Simone Assali, Oussama Moutanabbir Sicompatible quantum devices have been exploiting either tensile strained Si or compressively strained Ge QWs, which are the only group IV systems that can currently be routinely obtained using SiGe as growth template and barrier layers. For quantum information, the former has been used as the building block for electron spin qubits, whereas the latter has been explored in new schemes for hole spin qubits. Herein, we present a third lowdimension system consisting of highly tensile strained Ge QW integrated on an optically active platform and discuss its basic properties experimentally and theoretically. The growth of tensile strained Ge QW is achieved using direct bandgap GeSn as barrier layers grown on silicon wafers. This heterostructure yields high tensile strain in Ge QW and band structure corresponding to a sizable LHHH splitting exceeding 100 meV. Unlike compressively strained Ge, the top of the valence band is occupied by LH in tensile strained Ge. We also found a high LH gfactor anisotropy in Ge/GeSn QW, with g = 21.8 for inplane Bfield and g = 0.69 for perpendiculartoplane field. These properties lay the groundwork to implement LH spin qubits with potentially easier manipulation due to the combined effects of the large Rashbatype SOI, and the spin ½ of LH. 

C71.00228: Observation and stabilization of photonic Fock states in a hot radiofrequency resonator Mario Gely, Marios Kounalakis, Christian Dickel, Jacob Dalle, Rémy Vatré, Brian Baker, mark Jenkins, Gary Steele Detecting and manipulating singlephotons at MHz frequencies presents a challenge as, even at cryogenic temperatures, thermal fluctuations are significant. In our work [1], we use a GHz superconducting qubit to directly observe the quantization of a MHz radiofrequency electromagnetic field. Using the qubit, we achieve quantum control over thermal photons, cooling to the groundstate and stabilizing photonic Fock states. Releasing the resonator from our control, we directly observe its rethermalization dynamics with the bath with nanosecond resolution. Extending circuit QED to a new regime, we enable the exploration of thermodynamics at the quantum scale and allow interfacing quantum circuits with MHz systems such as spins or mechanical oscillators. The tool used to design such a circuit, QuCAT [2], the "quantum circuit analyzer tool in Python" will also be featured in this poster. 

C71.00229: SinglePhoton Dispersive Readout of a Qubit with a Photodetector: Theory Beyond the RotatingWave Approximation Andrii Sokolov, Eugene V Stolyarov We propose to use a singlephoton pulse and a photodetector for the dispersive readout of a qubit. The scheme avoids the shot noise errors. However, another source of errors makes it challenging to perform a singlephoton readout. To boost its performance, we propose to detune the qubit and the resonator further than usual, while coupling them stronger. The BlochSiegert shift then should be taken into account. It is shown how it can improve the readout. We provide simple analytical estimates for the readout contrast. Results of more complicated calculations that take the qubit relaxation into account are also presented. A contrast more than 75% can be achieved in 1μs for ideal detector and photon source. 

C71.00230: Study on the cavity photon induced dephasing of a transmon qubit in circuit QED due to the measurement microwave leakage Jisoo Choi, Gahyun Choi, Gwanyeol Park, Jinsu Son, KwanWoo Lee, SoonGul Lee, Woon Song, Yonuk Chong Qubit coherence is one of key features in quantum computing. In circuit QED architecture, it is known that the cavity photon induces dephasing of the qubit even in the dispersive regime [1, 2]. In this study, we studied in detail the dephasing of a 3D transmon qubit generated by the measurement microwave tone. First, we observed that the intense measurement microwave tone decreases the dephasing time. In order to avoid the dephasing, we controlled the mixer leakage by applying dcoffset voltage. We observed clear dependence of the measurement microwave leakage and dephasing, so that we can optimize our measurement setup to achieve maximum T_{2}^{*}. This calibration method is one of the standard features in our measurement system to preserve the qubit coherence. 

C71.00231: Enhancement in the crossresonance gate performance Xuexin Xu, Mohammad Ansari We theoretically model an experiment on a superconducting circuit made of a capacitively shunted flux qubit (CSFQ) and a transmon both capacitively coupled to a bus resonator in dispersive regime. We apply external driving microwave pulses over all energy levels and consider the transitions they impose effectively within the computational subspace. More specifically we apply entirely microwave twoqubit gate, the so called crossresonance, on CSFQ at sweet spot and away from it. Interestingly the twoqubit fidelity is largely enhanced at certain external flux away from the sweet spot. This enhancement takes place as the result of suppressed leakage out of computational subspace. 

C71.00232: Spectrum and Coherence of the CurrentMirror Circuit Daniel Weiss, Cheong Yiu Li, David Ferguson, Jens Koch The currentmirror circuit [1] exhibits a robust groundstate degeneracy and wave functions with disjoint support for appropriate circuit parameters. In this protected regime, Cooperpair excitons form the relevant lowenergy excitations. Based on a full circuit analysis of the currentmirror device, we introduce an effective model that systematically captures the relevant lowenergy degrees of freedom, and is amenable to diagonalization using Density Matrix Renormalization Group (DMRG) methods. We find excellent agreement between DMRG and exact diagonalization, and can push DMRG simulations to much larger circuit sizes than feasible for exact diagonalization. We discuss the spectral properties of the currentmirror circuit, and predict coherence times exceeding 1 ms in parameter regimes believed to be within reach of experiments. 

C71.00233: Qubit fast reset with QubiC Gang Huang, Yilun Xu, Ravi Kaushik Naik, Bradley Mitchell, David Santiago, Irfan Siddiqi Fast reset is a basic qubit control feedback loop where the hardware latency is critical. We develop the fast reset logic on the QubiC system by implementing the qubit status classification and the feedback loop in the FPGA firmware. The experiment setup and initial testing results are presented here. 

C71.00234: Exploring 3D architectures and superconducting interconnects using highly conformal ALD and CVD: a BEOLcompatible process for superconducting MgB_{2} David J Mandia, Devika Choudhury, Neil T Anderson, Gregory S Girolami, Jeffrey W Elam, Ali Nassiri, Angel YanguasGil The ability to fabricate 3D architectures and superconducting interconnects can be an enabling technology towards the scale up of quantum computing architectures. One of the key challenges is that physical vapor deposition methods, such as evaporation or sputtering, struggle to coat or infiltrate high aspect ratio structures, being traditionally limited to aspect ratios of 10:1 or lower. In this work we explore how to take advantage of the high conformality of ALD and some CVD processes to overcome this limitation. In particular, we have developed a BEOLcompatible, diboranefree process that is capable of growing superconducting magnesium diboride at low temperatures. This process has allowed us to demonstrate critical temperatures exceeding 20K in films that are just a few nm thick, and the formation of stable interfaces with oxide materials. Together with existing ALD processes for superconducting nitrides, we believe that this process can help us explore new device configuration, including the design of architectures with vertical junctions, or the development of superconducting interposers for advanced packaging applications. 

C71.00235: Impact of noise reduction in measurement of a super conducting flux qubit at 4.2 K Daisuke Saida, Narii Watase, Takehito Kamimura, Shingo Sobukawa, Hirohito Watanabe, Yuki Yamanashi A flux state of a super conducting flux qubit is evaluated at 4.2 K prior to measurement of quantum state at mK. At the 4.2 K measurement, a customized rod, where a sample is attached, is inserted in the Dewar vessel filled in the liquid helium. An elimination of artifact from an experimental system is crucial. In order to prevent signal quality deterioration by environmental noise, countermeasures have been taken by strengthening the electrostatic shield and introducing the twisted pair wiring. Low noise voltage source (LP6016) for bias current control of SQUID is also effective in suppressing signal fluctuation from SQUID. As a result, noise density at 50 Hz and 150 Hz in the measurement became 1/300 and 1/500 compared to the previous experiment, respectively. We evaluated the flux state in the super conducting flux qubit through an observation of signal in a readoutSQUID. This sample was fabricated by AIST Nb standard process 2, where J_{c} was 25 μA/μm^{2}. On a flux dependence of threshold current (I_{th}) in the readoutSQUID, standard deviations (σ) of I_{th} was 0.16. This indicates that we can control an operating point of the readoutSQUID in an accuracy of the measurement with an order less than 1 μA. Further, σ << 1 was evaluated when we observed flux conditions in the qubit. 

C71.00236: Search by Lackadaisical Quantum Walk with Nonhomogeneous Weights Mason Rhodes, Tom Wong The lackadaisical quantum walk, a quantum walk with weighted selfloops, speeds up dispersion on a line and improves spatial search on the complete graph and periodic square lattice. In these investigations, each selfloop had the same weight, due to each graph's vertextransitivity. In this paper, we propose lackadaisical quantum walks with selfloops of different weight. We investigate spatial search on the complete bipartite graph, which can be irregular with partitions of size N_{1} and N_{2}, which naturally leads to selfloops having different weights l_{1} and l_{2}, respectively. We prove that if the k marked vertices are confined to one partite set, then with the typical initial uniform state over the vertices, the success probability is improved from its nonlackadaisical value when l_{1}=kN_{2}/2N_{1} and N_{2}>(3−2√2)N_{1}, regardless of l_{2}. When the initial state is stationary under the quantum walk, however, the success probability is improved when l_{1}=kN_{2}/2N_{1 }without a constraint on the ratio of N_{1} and N_{2}. Next, when marked vertices lie in both partite sets, then for either initial state, there are many configurations for which the selfloops yield no improvement in quantum search, no matter what weights they take. 

C71.00237: Trimming Grover's Quantum Search Algorithm Grant Eberle, Gonzalo Ordonez Grover’s quantum algorithm is a complicated search algorithm made to run on a quantum computer. The algorithm allows users to search a database for a word in a significantly shorter time than a conventional computer. Past experiments have attempted to run iterations of the algorithm on a quantum computer and failed because of the complexity. My research modifies and simplifies the theory of Grover’s algorithm by utilizing results from previous work that studied the diffusion of wave functions across a hypercube. I have directly applied this diffusion process to an edited and simplified version of Grover’s algorithm based on the premise of simplifying the connections and paths between qbits represented on a hypercube. The algorithm I have created has been run and tested on the opensource quantum computer simulations provided by IBM on their IBM Q website. My results display a trimmed and practical version of Grover’s quantum search algorithm. 

C71.00238: Quantum simulations and force sensing experiments with 2D arrays of 100’s of ions Elena Jordan, Matthew Affolter, Kevin A. Gilmore, Athreya Shankar, Arghavan SafaviNaini, Robert J. LewisSwan, Murray J Holland, Ana Maria Rey, John Jacob Bollinger We perform quantum simulations and quantum sensing with twodimensional arrays of >100 trapped ions in a Penning trap [1, 2]. In our quantum sensing experiments, we measure small displacements of the ion crystal. Electric fields excite centerofmass (COM) motion of the crystal. By measuring the motioninduced spin precession we can determine the amplitude of the COM motion and the strength of the exciting field [2]. Improvements in the phase stability of our coupling lasers enabled phase coherent detection protocols, resulting in a single measurement sensitivity of 50 pm for the COM motion that was far offresonant with the trap axial frequency. 50 pm is about a factor 40 below the size of the ground state wavefunction.Further, we show results of electromagnetically induced transparency (EIT) cooling for the drumhead motion of the singleplane arrays [3, 4]. We present results that show simultaneous cooling of all the drumhead modes to close to the ground state of motion. 

C71.00239: WITHDRAWN ABSTRACT


C71.00240: QAOA Algorithms for Traveling Salesman Problem Revisited Changyuan Liu The traveling salesman problem is a traditionally NPhard problem. Earlier quantum algorithm encodes the qubits based on vertices, while we encode the qubits based on edges, with a resources requirement halved. With edge encoding scheme, QAOA algorithm is demoed with small cases, on a classical enumlator, with the optimal solutions successfully found. The algorithm has polynomial complexity in terms of the number of quantum operations. 

C71.00241: Implementation of excited state energy and its analytical derivatives for photochemical reaction simulations on NISQ devices Yohei Ibe, Takahiro Yamamoto, Yuya O. Nakagawa, Kosuke Mitarai, Tennin Yan, Gao Qi, Takao Kobayashi A primitive but still powerful form of quantum computers called Noisy IntermediateScale Quantum (NISQ) devices is about to be utilized for the realworld problems. NISQ devices have a few hundreds to thousands of qubits under highly precise control although they are not faulttolerant. 

C71.00242: The Quantum Alternating Operator Ansatz on Maxk Vertex Cover Jeremy Cook, Stephan Eidenbenz, Andreas Bärtschi We study the performance of the Quantum Alternating Operator Ansatz (a generalization of the QAOA for problems with hard constraints) on the problem of Maxk Vertex Cover due to its modest complexity, while still being more complex than the well studied problems of MaxCut and MaxE3LIN2. Our approach includes (i) a performance comparison between easytoprepare classical states and Dicke states, (ii) a performance comparison between two XYHamiltonian mixing operators: the ring mixer and the complete graph mixer, (iii) an analysis of the distribution of solutions via Monte Carlo sampling, and (iv) the exploration of efficient angle selection strategies. Our results are: (i) Dicke states improve performance compared to easytoprepare classical states, (ii) an upper bound on the simulation of the complete graph mixer, (iii) the complete graph mixer improves performance relative to the ring mixer, (iv) the standard deviation on the distribution of solutions decreases exponentially in p (the number of rounds in the algorithm), requiring an exponential number of random samples find a better solution in the next round, and (iv) a correlation of angle parameters which exhibit high quality solutions that behave similarly to a discretized version of the Quantum Adiabatic Algorithm. 

C71.00243: Optimizeraware Circuit Design for Error Unfolding in Variational Quantum Eigensolver Wim Lavrijsen, Miroslav Urbanek, Mekena L Metcalf, Juliane Müller, Benjamin Nachman, Diana Chamaki, Costin Iancu, Wibe A De Jong Quantum hardware suffers from errors and any measured output is thus a convolution of the intended result and some error distribution. The Variational Quantum Eigensolver has a classical optimizer step that takes the output from the quantum chip to determine the input parameters for the next iteration. Errors can prevent the optimizer from making progress; and if they are too large, make it impossible to calculate, let alone find, the global minimum. If the error distribution were known, it could be unfolded, but this is generally not the case, especially if the errors do not commute with the whole circuit. Exploiting ideas from randomized compilation, we introduce twirl gates into the circuit, generating logically equivalent circuits with the same number of gates and same output, but with different error behavior. The physical processes do not change, thus error rates remain the same as well. Using a Markov chain as error model, we apply a maximum likelihood fit to find those rates that produce migration matrices for unfolding consistent with all observed distributions. This results in improved output estimates of the quantum computer, and better defined uncertainties as input to the classical optimizer leading to faster convergence and a more robustly defined global minimum. 

C71.00244: Benchmarking Noise Extrapolation with OpenPulse Eugen Dumitrescu, Raphael Pooser, John Garmon In order to augment digital qubit metrics, such as gate fidelity, we discuss analog error mitigability, i.e. the ability to accurately distill precise observable estimates, as a hybrid quantumclassical computing benchmarking task. Specifically, we characterize singlequbit error rates on IBM’s Poughkeepsie superconducting quantum hardware, incorporate control mediated noise dependence into a generalized rescaling protocol, and analyze how noise characteristics influence Richardson extrapolationbased error mitigation. Our results identify regions in the space of Hamiltonian control fields and circuitdepth which are most amenable to reliable noise extrapolation, as well as shedding light on how lowlevel hardware characterization can be used as a predictive tool for uncertainty quantification in error mitigated NISQ computations. 

C71.00245: Modeling Quantum Devices and the Reconstruction of Physics in Practical Systems Hang Ren, Ying Li Modeling quantum devices is to find a model according to quantum theory that can explain the result of experiments in a quantum device. We find that usually we cannot correctly identify the model describing the actual physics of the device regardless of the experimental effort given a limited set of operations. According to sufficient conditions that we find, correctly reconstructing the model requires either a particular set of pure states and projective measurements or a set of evolution operators that can generate all unitary operators. 

C71.00246: Continuousvariable QKD network in Qingdao Yichen Zhang, Ziyang Chen, Binjie Chu, Chao Zhou, Xiangyu Wang, Yijia Zhao, Yifan Xu, Chao Xu, Hongjie Wang, Ziyong Zheng, Yundi Huang, Chunchao Xu, Xiaoxiong Zhang, Tao Shen, Ge Huang, Yunwu Zheng, Zhaoxuan Fei, Weinan Huang, Menglin Zhu, Luyu Huang, Bin Luo, Song Yu, Hong Guo Continuousvariable quantum key distribution (QKD) is a very attractive method for the physical layer protection of information transmission by secure distribution of private keys, as it uses standard telecom components that operate at room temperature and it has higher secret key rates (bits per channel use) over metropolitan areas. The longest distance of continuousvariable QKD field tests has reached 50 km, which is enough to support the construction of metropolitan networks. Here, we report the longterm performance of three nodes continuousvariable QKD network in Qingdao, which is the first continuousvariable QKD application demonstration with clear application scenarios over a long period of time through existing commercial optical fiber links. The average secret key rate achieves higher than 12.00 kbps over 71.03 km optical fiber line. The system has been running for 28 days stably with a reliable performance, which paves the way to deploy continuousvariable QKD in metropolitan settings. 

C71.00247: Continuousvariable sourcedeviceindependent quantum key distribution Yichen Zhang, Ziyang Chen, Christian Weedbrook, Bin Luo, Song Yu, Hong Guo The continuousvariable quantum key distribution with entanglement in the middle, a semideviceindependent protocol, places the source in the untrusted third party between Alice and Bob, and thus has the advantage of high levels of security with the purpose of eliminating the assumptions about the source device. However, previous works considered the collectiveattack analysis, which inevitably assumes that the states of the source has an identical and independently distributed (i.i.d) structure, and limits the application of the protocol. To solve this problem, we modify the original protocol by exploiting an energy test to monitor the potential high energy attacks an adversary may use. Our analysis removes the assumptions of the light source and the modified protocol can therefore be called sourcedeviceindependent protocol. Moreover, we analyze the security of the continuousvariable sourcedeviceindependent quantum key distribution protocol with a homodynehomodyne structure against general coherent attacks by adapting a stateindependent entropic uncertainty relation. The simulation results indicate that, in the universal composable security framework, the protocol can still achieve high key rates against coherent attacks under the condition of achievable block lengths. 

C71.00248: ResourceAdaptable Quantum Algorithms for Scalable Simulation of the Schwinger Model Alexander Shaw, Natalie M Klco, Pavel Lougovski, Jesse Stryker, Nathan Wiebe The Schwinger model (quantum electrodynamics in 1+1 dimensions) is a testbed for the study of field theories underpinning the Standard Model. Quantum computers are anticipated to enable unprecedented simulations of field theories. In this work, we give scalable and explicit digital algorithms to simulate the Schwinger model using faulttolerant quantum computation. We upper bound a relevant metric of computational complexity, the number of Tgates, in terms of the simulation parameters, confirming that the time evolution can be simulated efficiently. Additionally, we give circuits that could be used in a nearerterm (NISQ) implementation of our simulation algorithms. 

C71.00249: SpaceTime Mixing of Quantum Computing in an Entangled Atomic Chain and Time Crystals Andrew Van Horn, ChengHsiao Wu


C71.00250: Employing Variational Principles to Define the Effective Hamiltonian of a Periodically Driven Qubit Daniel Zeuch, David Peter DiVincenzo The trajectory of a linearly driven qubit in the rotating frame can be determined using the effective Hamiltonian introduced in [1], which improves on the rotating wave approximation. By its definition, this Hamiltonian (i) is analytic in time and, (ii), yields an effective drivenqubit trajectory that coincides with the exact trajectory at equallyspaced points in time. In general, these effective trajectories are significantly smoother than the exact ones. The effective Hamiltonian is determined by an infinite sum whose convergence, however, is not always guaranteed [1]. As the requirements (i) and (ii) are fulfilled by a continuum of Hamiltonians, here we hypothesize that the effective Hamiltonian additionally satisfies, (iii), a variational principle that is motivated by the smoothed trajectories mentioned above. Our variational principles state that the integral of a certain function of the Hamiltonian, e.g., its positive eigenvalue, over the full pulse duration is minimized by the effective Hamiltonian of [1]. To find evidence for or against our hypotheses, we carry out variational calculations aimed at numerically minimizing the corresponding integrals. 

C71.00251: Entangled Excitons via Spontaneous Downconversion Ariel Shlosberg, Mark T. Lusk A class of centrosymmetric molecules support excitons with a welldefined quasiangular momentum. Cofacial arrangements of these molecules can be engineered so that quantum cutting produces a pair of excitons with angular momenta that are maximally entangled. The Bell state constituents can subsequently travel in opposite directions down molecular chains as ballistic wave packets. This is a direct excitonic analog to the entangled polarization states produced by the spontaneous parametric downconversion of light. As in optical settings, the ability to produce Bell states should enable foundational experiments and technologies based on nonlocal excitonic quantum correlation. The idea is elucidated with a combination of quantum electrodynamics theory and numerical simulation. 

C71.00252: Practical route to entanglementenhanced communication over noisy bosonic channels Haowei Shi, Zheshen Zhang, Quntao Zhuang Entanglement can offer substantial advantages in quantum information processing, but loss and noise hinder its applications in practical scenarios. Although it has been well known for decades that the classical communication capacity over lossy and noisy bosonic channels can be significantly enhanced by entanglement, no practical encoding and decoding schemes are available to realize any entanglementenabled advantage. Here, we report structured encoding and decoding schemes for such an entanglementassisted communication scenario. Specifically, we show that phase encoding on the entangled twomode squeezed vacuum state saturates the entanglementassisted classical communication capacity and overcomes the fundamental limit of covert communication without entanglement assistance. We then construct receivers for optimum hypothesis testing protocols under discrete phase modulation and for optimum noisy phase estimation protocols under continuous phase modulation. Our results pave the way for entanglementassisted communication and sensing in the radiofrequency and microwave spectral ranges. 

C71.00253: QuantumComputing(QC)? Not New and Not News! Merely Trendy Fashionable "Buzzwordism, Bandwagonism and Sloganeering for Fun, Profit, Survival, Ego" aka Showbiz! E. CarlLudwig Siegel QC has been alive and well since WWII in artificial neuralnetwork(ANN) artificialintelligence(AI), vs computingquanta since quantumtheory, if not Newcomb(1881)Poincare(1911)Weyl(1916)...Benford(1938)[benfordonline.net] digits loglaw inverse[Antonoff/Siegel(2002)]: digits=bosons. What does QC mean? In ANN AI, not counting Turing(1936 machine plagarism of LenzIsing model(1911) of localized magnetism, starting with Rosen(SRI). In the 1980s Charles Rosen(MachineIntelligence), Jacob Goldman(Xerox PARC), Irwin Wunderman(HP), Vesco Marinov and Adolph Smith(Exxon Enterprises/AI) and Edward Siegel realized that ubiquitous standard sigmoid onsite switchingfunction N/[1+exp(E/T)]=N/[+1+exp(E/T)]=N/[exp(E/T)+1] FermiDirac quantimstatistics trapping the ANN in nonoptimal localminima necessitating time and memory costly Boltzmannmachine followed by simulatedannealing to eliminate the +1 converting FermiDirac quantumstatistics into MaxwellBoltzmann classicalstatistics. They realized this time and memory costly crutch could be eliminated by reversing sigmoidfunction to N/[exp(E/T)1] BoseEinstein quantumstatistics["Eureka!"] and then taking the limit as N approaches infinity. BoseEinstein condensation (BEC) ["Shazam!"] blindingly quick ANN AI QC (N)BECmachine. 

C71.00254: Quantum feedback error correction of a monitored system evolving adiabatically Ka Wa Yip, Mostafa Khezri, Daniel A Lidar We devise a quantum feedback error correction method to reverse the effect of thermal excitations in quantum annealing. Conditioned on the output signal I(t) from continuous measurement records, feedback is applied to an adiabatically evolving system in the hopes of increasing the ground state population at the end of the anneal. We propose an experimental setting for such continuous measurement and feedback in the case of superconducting flux qubits. We simulate the error correction performance of a system weakly coupled to a thermal bath based on methods like quantum trajectories and quantum bayesian updates. We also derive a feedback master equation for markovian feedback (feedback delay $\tau\rightarrow 0$) and further give the timescale condition for feedback Markovianity. Realistic feedbacks are also subjected to nonnegligible feedback delay, detector efficiency, and restrictions on the form of the feedback Hamiltonian due to experimental challenges. We therefore study the effectiveness of feedback correction under such limitations and explore how the optimized feedback delay time depends on the annealing schedule and limitations in other experimental parameters. 

C71.00255: Constructing parsimonious control functions using Bsplines with carrier waves N. Anders Petersson, Fortino Garcia, Jonathan L DuBois We consider the optimal control problem for realizing logical gates in closed quantum systems, where the evolution of the state vector is governed by the timedependent Schroedinger equation. The number of parameters in the control functions is made independent of the number of time steps by expanding them in terms of Bspline basis functions, with and without carrier waves. We use an interior point gradientbased technique from the IPOPT package to minimize the gate infidelity subject to amplitude constraints on the control functions. The symplectic StromerVerlet scheme is used to integrate a realvalued formulation of Schroedinger's equation in time and the gradient of the gate infidelity is obtained by solving the corresponding adjoint equation. This allows all components of the gradient to be calculated at the cost of solving 3 Schroedinger systems, independently of the number of parameters in the control functions. The method is applied to Hamiltonians that model the dynamics of several coupled superconducting qubits. We find that including judiciously chosen frequencies in the carrier waves of the basis functions can significantly reduce the number of parameters and lead to smoother control functions. 

C71.00256: Learning Quantum Error Models William Moses, Costin Iancu, Wibe A De Jong In this abstract we propose a methodology for learning quantum error models from experimental data. This information is useful for characterizing the effectiveness of hardware, predicting how well a circuit should run in practice, and synthesizing corrected circuits that attempt to perform better by taking the error model into account. 

C71.00257: An information entropy interpretation of photon absorption by dielectric media Sung Wook Han, Purevdorj Munkhbaatar, Kim MyungWhun We measured photon absorption in dielectric media and proposed the photonversion Beer–Lambert’s law to quantify the absorption. We used a Hong–Ou–Mandel interferometer and 810 nm twinphotons. We found that the depth ratio of the null point in the interference patterns of the interferometer agreed with the classical transmittance of the samples. We established a statistical model of the photon absorption process and proposed an information entropy interpretation to understand the meaning of the Beer–Lambert law. Comparisons of the results of the photon absorption experiments with classical experiments demonstrate the validity of our model and interpretation. 

C71.00258: Simulating broken PTsymmetric Hamiltonian systems by weak measurement Minyi Huang, RayKuang Lee, Lijian Zhang, ShaoMing Fei, Junde Wu By embedding a PTsymmetric (pseudoHermitian) system into a large Hermitian one, we disclose the relations between PTsymmetric quantum theory and weak measurement theory. We show that the weak measurement can give rise to the inner product structure of PTsymmetric systems, with the preselected state and its postselected state resident in the dilated conventional system. Typically in quantum information theory, by projecting out the irrelevant degrees and projecting onto the subspace, even local broken PTsymmetric Hamiltonian systems can be effectively simulated by this weak measurement paradigm. 

C71.00259: Knowledge is the Foundation of the Functioning of the Physical World in QM:Everything Goes Through the Wave Function,IncludingNullMeasurements,Expansion of On the Nature of the Change in the Wave Function in A Measurement in Quantum Mechanics(arxiv,1995) Douglas Snyder Nothing in quantum mechanics (qm) occurs without the involvement of the wave function (wf); the wf is nonphysical. When a measurement is made of 1 quantity, a new wf accompanies the measurement wherein another quantity of the particle is uncertain due to the wf, eg, position requiring many superposed waves and momentum requiring only 1 wave. Many situations showing the indispensability of the wf are discussed. What prevents knowledge based on the wf from being acknowledged as the foundation of the physical world is the assumed unavoidable physical interaction (pi) between the measuring instrument and the physical entity measured in the change in the wf in a measurement. This is explored in part through Feynman’s jolt of a photon on an electron in his 2 slit experiment with a light source between the 2 slits. The origin of this assumed unavoidable pi appears to be Bohr’s description of complementarity. The source for Bohr appears the psychologist W. James who did not include this pi in his complementarity. Without this pi, the central role of the wave function and knowledge derived from it is clearly seen in quantum mechanics. With null measurements (no pi), the problem that appears to originate with Bohr cannot be avoided. It should not have been avoided in 1995. 

C71.00260: The Quantum Theory of Entanglement and Alzheimer's Shantilal Goradia "Feynman argued that if gravity is indeed a quantum phenomenon, a superposition of a particle in two places at once would create two separate gravitational fields in case of a small mass in a quantum superpostion (entanglement), two different spacetimes would coexist side by side, almost like two separate universes, a state of affairs that should not exist in Einstein's theory [1]." We show gravity as a quantum phenomenon in [2] leading to [3], [4] and [5]. Here, we illustrate such coexistances. As a light bulb filled with white light, one universe so to say, is equivalent to one filled with seven different colors of light. [1] Folger T (2019) Quantum gravity in the lab. Scientific American, [2] Goradia SG Newtonian gravity in natural units. (2012) Journal of Physical Science and Application 2: 265268, [3] Goradia SG Dark matter from our probabilistic gravity. (2015) J of Physical Science and Application 5: 373376, [4] Goradia SG The Quantum Theory of Entanglement and Brain Physics, (2018) Journal of Clinical Review & Case Reports, [5] Goradia SG The Quantum Theory of Entanglement and Alzeimer's. (2019) J Alzheimers Neurodegener Dis 5: 23. 

C71.00261: How Knowledge Leads to the Demise of Schrodinger’s Cat Through a Null Measurement (A Quantum Mechanical Measurement in Which There is No Physical Interaction Between the Measuring Instrument and the Entity Measured) Douglas Snyder The Schrodinger cat experiment (SCE) is presented. An alteration follows where the LACK of radioactive decay (rd) leads to the demise of the cat instead of the ACT of rd. The lack of rd is a negative (null) measurement (nm) (where there is NO physical interaction between the radioactive material and the Geiger counter). The nm is nontrivial because all knowledge about the radioactive material (rm) is derived from its associated wave function (wf) which itself has no physical existence. The wf is how we make probabilistic predictions regarding systems in quantum mechanics. Before the box in the SCE is opened, the wf for the rm is: psi_rm = 1/√2 [psi_rm does not decay + psi_rm does decay] which leads to the possibility of interference before the cat is observed. As Schrodinger wrote: “The psi_function of the entire system [including rm and cat] would express this by having in it the living and the dead cat (pardon the expression) mixed or smeared out in equal parts.” The wf is the foundation for knowledge since the probabilities are derived from the wf and the wf contains all the information concerning a system. This alteration of the SCE emphasizes that the lack of rd in the original SCE is also a nm that leads to the continued life of the cat. 

C71.00262: A quantum mechanical interpretation of gravitational redshift of photon Donald Chang It was observed that electromagnetic waves can undergo a frequency shift in a gravitational field. This effect is important for satellite communication and astrophysical measurements. Previously, this redshift phenomenon was interpreted exclusively as a relativistic effect. Recently we found this effect can also be explained based on a quantum mechanical consideration. We propose that, due to the quantum nature of the photon, its effective mass is not zero. In a gravitational field, the total energy of the photon includes both its quantum energy and its gravitational energy. Then, the condition of energy conservation will require a frequency shift when the photon travels between two points with different gravitational potentials. This result suggests that the gravitational redshift effect of a photon is essentially a quantum phenomenon. This new understanding has a strong implication; it suggests that some of the previous experimental tests of general relativity need to be reinterpreted. 

C71.00263: From Hopf fiberation to dualityentanglement relation Yusef Maleki We show that the entanglementduality relation [Optica 5, 942 (2018)] can indeed be obtained, in its most generic form, from Hopf fiberation and stereographic geometry. We demonstrate that this relation is a natural consequence of the stereographic geometry, providing the first geometric approach to the notion of complementarity problem. We show that this geometry is dualityentanglement sensitive. This means that, it is sensitive to the wave nature, particle nature and entanglement nature of a single qubit. 

C71.00264: Programming multilevel quantum gates in disordered computing reservoirs via machine learning and TensorFlow Giulia Marcucci, Davide Pierangeli, Pepijn Pinkse, Mehul Malik, Claudio Conti Novel machine learning computational tools open new perspectives for quantum information systems. Here we adopt the opensource programming library TensorFlow to design multilevel quantum gates including a computing reservoir represented by a random unitary matrix. In optics, the reservoir is a disordered medium or a multimodal fiber. We show that trainable operators at the input and the readout enable one to realize multilevel gates. We study various qudit gates, including the scaling properties of the algorithms with the size of the reservoir. Despite an initial low slope learning stage, TensorFlow turns out to be an extremely versatile resource for designing gates with complex media, including different models that use spatial light modulators with quantized modulation levels.[1] 

C71.00265: Quantum Boosting Srinivasan Arunachalam, Reevu Maity Boosting is one of the most famous classical machine learning techniques (in theory and practice) that can construct a strong machine learning algorithm given access to a weak learning algorithm. It is natural to consider boosting in the quantum setting for the following reason: suppose we implement a quantum machine learning (QML) algorithm on a NISQ device, then the guarantees of the QML algorithm could be much worse than it was designed for, due to the noise in the quantum system. This motivates the question whether we can ``boost" the performance of a weak QML algorithm (implemented on a NISQ machine) to a *strong* QML algorithm? 

C71.00266: Layerwise learning for quantum neural networks Andrea Skolik, Jarrod McClean, Masoud Mohseni, Patrick van der Smagt, Martin Leib We introduce a layerwise learning strategy for parameterized quantum circuits. The circuit depth is incrementally grown during optimization, starting with a shallow circuit and adding depth until the required loss is attained. By training only varying subsets of the circuit’s parameters, we keep a fixed number of training parameters while increasing circuit depth until it is sufficient to represent the data. We then show that this approach avoids the problem of saddle points, or barren plateaus, of the error surface to a large extent due to the low depth of circuits, low number of parameters, and larger magnitude of gradients compared to training the full circuit. These properties make our algorithm ideal for execution on noisy intermediatescale quantum (NISQ) devices. We demonstrate our approach on an imageclassification task on handwritten digits, and show that the number of trained parameters can be decreased substantially while keeping gradient magnitudes larger than those of quantum circuits of the same size trained on a fixed architecture. 

C71.00267: Magnetic and electrical field detection using NVbased AFM Wentian Zheng We develop a homemade NVbased scanning microscopy to detect both magnetic and electrical field induced by tips we used. As for the magnetic field, the Ni tip is required to provide magnetic field and field gradient on the surface of diamond membrane. The ODMR shift is observed during the Ni tip moving around a NV center, and we observe isomagnetic circle by ODMR mapping which shrinks to about 20nm indicating the actual location of the NV center. 

C71.00268: Time resolved diamond magnetic microscopy of single transition metal magnetic nanoparticles Abdelghani Laraoui, Victor Acosta Understanding the magnetic properties of small transition metal magnetic nanoparticles (TMMNPs) can help in exploiting their useful properties such as high surfacetovolume ratio and tailorable surface chemistry for applications in catalysis, biosensing, and ultrahighdensity magnetic recording. At size below 10 nm, surface effects play a major role in determining their magnetic properties. Symmetry breaking of the crystal structure at the particle surface, dangling bonds, and surface strain can alter their properties. Accurate measurements of magnetic properties of single TMMNPs would therefore shed light on their critical properties. However, measuring these properties of such small particles at ambient conditions presents a great challenge due to the lack of sensitivity of current nonperturbative magnetic imaging techniques. Here we show recent measurements using magnetic microscopy based on nitrogen vacancy centers in diamond to measure the static and dynamic magnetic properties of individual 210 nm TMMNP (CoPt and FePt). Histograms of critical parameters such as magnetic anisotropy, saturation magnetization, and magnetic relaxation are extracted and correlated with morphology data taken by AFM, SEM, and TEM. 

C71.00269: Phase estimation in a multimode nonlienar interferometer. Narayan Bhusal, Jonathan P Dowling Simultaneous estimation of multiple phase shifts is very important in quantum metrology as it has implications for the singleshot quantum imaging. Multiparameter estimation has been already demonstrated in linear optics even though its performance is greatly limited by computational difficulty associated with matrix permanent. Here, we propose a scheme that uses nonlinear optical parametric amplification (OPA) to estimate multiple simultaneous phase shifts. The performance of our scheme is compared with the SNL and the Heisenberg limit (HL). We choose homodyne as the measurement strategy in our scheme. As photon loss is the biggest experimental limitation, we also investigate the effect of photon loss in the phase sensitivity. 

C71.00270: Rare Earth Quantum Information Science Decoherence TImes and Hosts Gavin Nop, Jonathan Smith We present a brief review of the current state of Quantum Information Science (QIS), with a focus on Quantum Information Processing (QIP) and the challenges posed by short decoherence times. Rare earth based systems have the potential to resolve many of the issues faced in QIS. Due to their 4f orbitals, rare earth atoms, when implanted into an appropriate host, demonstrate relatively high coherence times. We cover benefits and challenges regarding QIP, specifically quantum processing and optical quantum memory. We emphasize important results in recent experiments regarding rare earthbased quantum computers, and compare these results to the current state of the art in qubit design. Specifically, we perform electronic structure calculations for a rare earth iondoped wide band gap crystal and control quantum states offered by the doped ion. G.N. is grateful for an assistantship in the US DOE Office of Science, Science Undergraduate Laboratory Internship program. 

C71.00271: WITHDRAWN ABSTRACT


C71.00272: Experimental demonstration of the validity of the quantum heatexchange fluctuation relation in an NMR setup. Soham Pal, T.S. Mahesh, Bijay Agarwalla We experimentally explore the validity of the Jarzynski and Wöjcik quantum heatexchange fluctuation relation by implementing an interferometric technique in liquidstate nuclear magnetic resonance setup and study the heatexchange statistics between two coupled spin1/2 quantum systems. We experimentally emulate two models—(i) the XYcoupling model, containing an energy conserving interaction between the qubits, and (ii) the XXcoupling model—and analyze the regimes of validity and violation of the fluctuation symmetry when the composite system is prepared in an uncorrelated initial state with individual spins prepared in local Gibbs thermal states at different temperatures.We further extend our analysis for heat exchange by incorporating correlation in the initial state. We support our experimental findings by providing exact analytical results. Our experimental approach is general and can be systematically extended to study heat statistics for more complex outofequilibrium manybody quantum systems. 

C71.00273: Collective enhancements in charging quantum batteries via a quantum heat engine Kosuke Ito, Gentaro Watanabe As a model of socalled quantum battery, a quantum system as an energy storage, we study the charging of many twolevel systems via a quantum heat engine. Especially, we focus on the collective effects in the charging. We show that the collective charging outperforms in the amount of the stored energy, its fluctuation, and the charging speed in comparison to the individual one. In the collective charging, symmetry of the interaction between the engine and the battery causes emergent bosonic quantum statistics, which result in a collective high probability excitation. 

C71.00274: Controlling quantum dot level spacing: moving beyond the constant interaction model Zachary Parrott, Jackson Kuklin, Bradley Lloyd, Megan Smith, Meenakshi Singh Proposed large scale implementation of gate defined semiconductor quantum dots requires effective means to tune each dot to desired tunnel coupling, capacitive coupling to gates, and coupling to sources of decoherence such as the phonon bath. These parameters are currently understood within the context of the constant interaction model that predicts a periodic level spacing based on a constant capacitance of each dot to the relevant gates. Yet, the actual capacitance of the dot is not a constant and depends on parameters including the electron number, voltage of the associated gates, and size of the dot, leading to a nonlinear level spacing. We show how taking these parameters into consideration enables greater control of each quantum dot. We also present a means to change the dot level spacing, thereby changing the coupling to the phonon bath, while maintaining desired tunnel coupling in a framework similar to virtual gating for cross capacitance. The results are relevant to minimizing decoherence in quantum dot qubits. 

C71.00275: Autotuned quantum dots in silicon as a candidate platform for scalable quantum computing and quantum neuromorphic devices Bradley Lloyd, Megan Smith, Zhexuan Gong, Meenakshi Singh Spin qubits in gate defined quantum dots in silicon present a robust architecture for quantum information processing due to long coherence times, tuneability, and scalability. However, the fabrication of such qubits leads to strong device variability, making it challenging to scale up the number of qubits for quantum computing applications. To address this challenge, we present our new device design and an automation protocol development to tune individual qubits. This automation protocol works to counteract device variability, resulting in greater scalability and versatility for the device. From this versatility we will explore the potential of using these autotuned quantum dots as quantum neuromorphic devices by engineering a nonMarkovian bath for one or more qubits. 

C71.00276: A tunable coupler for suppressing ZZ crosstalk and realizing multiform two qubitgates Tianqi Cai, Xiyue Han, Zenghui Bao, Zhiling Wang, Hongyi Zhang, Yipu Song, Luming Duan


C71.00277: WITHDRAWN ABSTRACT


C71.00278: THz Sommerfeld Wave Propagation on Superconducting Niobium Wire for MillimeterWave Interconnects Bharat Kuchhal, Emma Snively, Kevin Multani, Hubert Stokowski, Amir SafaviNaeini, Paul B. Welander, Emilio Nanni Although there has been a stupendous development of superconducting microwave circuits, scalability and transmission of quantum information remain important issues. One approach involves the transduction of quantum information from microwave to millimeterwave frequencies prior to transmission. For efficient transmission of THz waves, the development of millimeterwave interconnects is a vital challenge. In this pursuit, we propose to transmit Sommerfeld waves in the THz regime on the surface of a single superconducting Niobium wire connected between a pair of horn antennas and Wband (75 – 110GHz) waveguides. The Sommerfeld mode on single conductors in the THz frequency range have demonstrated very low losses with room temperature conductors. Compared to the room temperature, our calculations show an increase in conductivity of superconducting Niobium by two orders of magnitude, which indicates significantly lower losses are possible for links at a few Kelvin. 

C71.00279: Disorderfree localization in the Kitaev Honeycomb Model Adrian Chapman, Sayonee Ray We study operator propagation and scrambling in the twodimensional Kitaev honeycomb model. An exact solution for this model allows us to calculate the infinitetemperature outoftimeordered correlator for Pauli observables, where we find that the infinitetemperature average over gauge sectors manifests as a disorder average for this quantity. This induces a localization effect for observables in the bond algebra of the Hamiltonian, while observables outside of the algebra completely scramble. We interpret our result in terms of the diffusion of Pauli strings, whose endpoints are localized yet whose interiors propagate freely. We further find that, in the ground state gauge sector of the model, operators do not localize. We further extend our analysis to the finite temperature regime using Monte Carlo MetropolisHastings methods. 

C71.00280: DATA SCIENCE


C71.00281: Combinatorial fabrication and spectroscopic analysis of FeCoCr ternary alloy thin film Tadashi Nishio, Masahiro yamamoto, Takuo Ohkochi, Masato Kotsugi The development of a highthroughput experiment is an important issue in materials informatics, especially for materials discovery. Recently, combinatorial deposition and highthroughput analysis are rapidly progressed [1]. However, the combination of material fabrication and property analysis still leaves much room for development. Particularly, a question is raised about whether comprehensive phase diagram mapping is the optimum solution for materials discovery. 

C71.00282: Normal mode analysis of a relaxation process with Bayesian inference Itsushi Sakata, Yoshino Nagano, Yasuhiko Igarashi, Shin Murata, Kohji Mizoguchi, Ichiro Akai, Masato Okada Relaxation processes provide many insights into atomic/molecular structures and the kinetics and mechanisms of chemical reactions. 

C71.00283: Predicting Ionic Liquids Properties with MachineLearning Zafer Acar, Michael Munje, Phu Nguyen, Kahchun Lau


C71.00284: Interpretable modeling by linearly independent descriptor generation method Hitoshi Fujii, Tamio Oguchi For interpretable modeling, linear regression combining descriptor generation and selection operator, such as approach of Ghiringhelli[1] and Ouyan[2], is very effective. However, multicollinearity (MC) (and near multicollinearity) between descriptors that are problematic in linear regression analysis can reduce the quality of the descriptor selection. Therefore, we proposed the linearly independent descriptor generation (LIDG) method[3] that generates descriptors while removing MC. This approach can improve their approach. 

C71.00285: Artificial Intelligence to detect gravitational waves from a network of detectors Thilina Shihan Weerathunga The application of artificial intelligence in astronomical data analysis is becoming more popular among the scientific community. In our recent work [1,2], we have shown the effectiveness of Particle Swarm Optimization (PSO), a wellknown algorithm in the field of swarm intelligence, in addressing signal detection and parameter estimation problem related to gravitational waves from compact binary coalescences (CBCs). The fully coherent network analysis of data from multiple gravitational wave (GW) detectors is computationally expensive since it is associated with a high dimensional numerical optimization problem. In our previous work, we showed using a nonspinning 2.0 postNewtonian order waveform and four gravitational wave detectors (two LIGO detectors, Virgo and Kagra) that PSO can achieve the same performance as a grid search with less than 200,000 templates for a component mass range of 1.0 to 10.0 solar masses at a network signal to noise ratio of 9. Currently, we are increasing the dimensionality of the optimization problem by adding spin parameters to the waveform and exploring the effectiveness of the algorithm. 

C71.00286: Machine learning to predict microbial community traits driving carbon fixation Jaron Thompson Microbial communities are ubiquitous influencers of macroscopic environments, yet overwhelming complexity makes it difficult to decipher functional relationships between specific microbes and ecosystem properties. Integrating advances in DNA sequencing technology with computational approaches like machine learning (ML) could address this problem. In [Thompson et al, PLoS One, 2019], we applied neural networks, random forest models, and indicator species analyses to correlate microbiome data (16S rRNA gene profiles) with dissolved organic carbon (DOC) content after 44 days of plant litter decomposition. We analyzed 300+ soil microcosms, including 1709 total bacterial operational taxonomic units (OTUs), and performed multiplemodel feature reduction. We are now leveraging Bayesian network structure learning to infer mechanistic interactions between microbial species abundance and DOC. After training a Bayesian network model using pine litter data, we predict DOC results of independent oak litter experiments and demonstrate that relationships between microbial species abundance and DOC are conserved across litter types. 

C71.00287: ParaMonte: A highperformance parallel library for MonteCarlo optimization, sampling, and integration Fatemeh Bagheri, Amir Shahmoradi At the foundation of predictive science lies the scientific methodology, which involves multiple steps of observational data collection, developing testable hypotheses, and making predictions. Once a scientific theory is developed, it can be cast into a mathematical model whose parameters have to be fit via observational data. This leads to the formulation of a mathematical objective function for the problem at hand, which has to be then optimized to find the bestfit parameters of the model or sampled to quantify the uncertainties associated with the parameters, or integrated to assess the performance of the model. Toward this goal, a highly customizable, userfriendly highperformance parallel Monte Carlo optimizer, sampler, and integrator library is presented here which, can be used on a variety of platforms with single to manycore processors, with interfaces to popular programming languages including Python, and Fortran/C/C++. In particular, we discuss the parallel implementation of a variant of Markov Chain Monte Carlo known as Delayed Rejection Adaptive Metrolpolis (DRAM) and its scalability 

C71.00288: COMPUTATIONAL PHYSICS


C71.00289: Building a DLS Device to Measure In Situ Glycine Cluster Formation Hannah Fejzic, Bruce Allen Garetz, Omar Gowayed Laser trapping nucleation uses optical tweezers focused at the airsolution interface to grow crystals. Research has shown that focusing a continuous wave (CW) laser at the glasssolution interface of a solution of glycine in deuterium oxide, does not lead to nucleation, but to laserinduced phase separation (LIPS) droplet formation. The LIPS droplet is about double the concentration of the initial solution, past the metastable zone. This droplet is believed to be made up of large, liquidlike clusters of glycine that are organized in a size gradient with larger clusters in the center of the solution. 

C71.00290: Firstprinciples calculations study of electronic structure, optoelectronic, vibrational analysis, linear and nonlinear optical properties of 4,5dibromo2,7 dinitrofluorescien Jean Baptiste Fankam Fankam Theoretetical inverstigation on 4,5dibromo2,7 dinitrofluorescien at the RHF level and different DFT with the ccpVDZ basis set with the help of Gaussian 09 suit of program software. We have firstly modeled and optimized the geometry of the structure and further, we have computed the frequencies' analysis to understand the thermodynamic, optoelectronic, linear and nonlinear optical properties. As far as this analysis is concerned, we have also been able to come out successful with a well calculated chemical reactivity and stability of the molecule through frontier molecular orbitals defined by the higher occupied and lower unoccupied molecular orbitals (EHOMO and ELUMO). Our results insinuate that this molecule has a potential application in linear and nonlinear optical materials, and optoelectronic devices due to his large hyperpolarizability and can be a promising compound for optical limiting applications. Presently, no experimental and theoretical values in literature were determined for the above properties are available, we are hopeful that our final results will provide important information for further studies of this compound in NLO materials and optoelectronic devices. 

C71.00291: Computational Synthesis of 2D Materials: A HighThroughput Approach to Materials Design Tara Boland, Arunima Singh The emergence of two dimensional materials opened up many potential avenues for novel device applications such as nanoelectronics, topological insulators, field effect transistors, microwave and terahertz photonics and many more. To date there are over 1,000 theoretically predicted 2D materials. Only 55 2D materials have been experimentally synthesized. Computational methods such as density functional theory can be used to determine the suitable substrates to synthesize 2D materials. Using various 2D materials databases and van der Waals corrected density functional theory we investigate the suitability of 12 substrates to stabilize 2D growth. For materials which meet the criteria for suitable substrateassisted synthesis methods such as chemical vapor deposition or mechanical exfoliation, the density of states is computed to characterize the electronic properties of these materials for device applications. 

C71.00292: Predicting the properties of ultrathin magnetic H_{x}CrS_{2} from first principles and machine learning Daniel Wines, Jaron Kropp, Can Ataca An air stable H_{x}CrS_{2} layered material has been synthesized by soft chemical methods, which can be exfoliated down to ultrathin layers, providing a promising path for the synthesis of twodimensional (2D) magnets^{1}. Although a reliable synthesis method has been developed, the atomic structure is still unknown. Variables such as Cr vacancies and H impurities must be determined in order to understand the properties of this material for device applications. We used a combination of density functional theory (DFT), molecular dynamics (MD) and cluster expansion formalism to study the energetics as a function of Cr vacancies and H impurities. From here, we studied the stability, electronic and magnetic properties of these H_{x}CrS_{2} structures and examined the effect of layering on these properties. In order to extend our calculations to a wider range of structures, we trained a machine learning algorithm with our DFT and MD calculated data to predict the properties of other H_{x}CrS_{2 }based materials outside our training set. 

C71.00293: Novel SolidState Electrolytes for Li Ion Batteries by Computational Design and Highthroughput Ab Initio Calculation Wonseok Jeong, Youngho Kang, Seungwu Han Solidstate electrolytes (SSEs) can alleviate many of the issues of Liion batteries arising from the utilization of the organic liquid electrolytes. Up to date, several SSEs have been proposed from previous experiments or computational screening from publicly available materials databases, however, none of those SSEs are fully satifactory. In this work, we take one step further; instead of simply exploring a preexisting materials database, we try to design new materials with aliovalent substitution of cations. This aliovalent substituion is known to facilitate kinetics of Li diffusion. We first screen potential host materials for generating new SSEs by aliovalent substituion, considering fundamental properties such as the presence of transition metals, thermodynamic stability, and band gap. Afterward, we crudely examine the potential energy surface (PES) around the Li ion at interstitial sites. The materials with the most smooth PES are then chosen for the possible candidate for the host material. Finally, we choose some materials from the candidate list and demonstrate that indeed they become a Li ion conductor after aliovalent doping. Starting from 42,337 structures, we find a number of SSEs with predicted Li ionic conductivity comparable to the stateoftheart Li_{10}GeP_{2}S_{12}. 

C71.00294: COMPUTATIONAL STUDY OF THE INTERACTION OF A WATER MOLECULE WITH 2DHBN(TWODIMENSIONAL HEXAGONAL BORON NITRIDE) AND WITH TI2DHBN. Gregorio RuizChavarria After graphene synthesis in 2004 many two dimensional systems has been studied, since the possible applications of these are many. In this work I made a computational study of the interaction of a water molecule with two dimensional hexagonal boron nitride(2DHBN). First the stability of the 2DHBN is obtained using Density Functional Theory, Atomic Pseudopotentials,BornOppenheimer approximation and molecular dynamics. Next I cause this system to interact with a water molecule. In a second moment, I made a computational study the stability of the system 2DHBN, but adding a Titanium atom, the system TI2DHBN. Again I provoke the interaction between a water molecule and the TI2DHBN system. I show the results of my calculations, and these are compared with other computational and experimental results. 

C71.00295: Realspace Moiré potential, lattice corrugation, and band gap variation in a MoTe_{2}/MoS_{2} heterobilayer WenTong Geng, Vei Weng, Takahisa Ohno, Jun Nara To have a firstprinciples description of the Moiré pattern in a transition metal dichalcogenide heterobilayer, we have carried out DFT calculations, taking full accounts of both atomic registry in and the lattice corrugation out of the atomic layers, on a MoTe_{2}/MoS_{2} system which has a moderate size of superlattice larger than an exciton yet not large enough to justify a continuum model treatment. We find that the local potential in the midplane of the bilayer can serve as an excellent illustration of the Moiré pattern in the van der Waals heterostructure. In the Mo atomic planes, the array of local potential planar maximum (LPPM), rather than the local potential itself, makes the Moiré pattern more obvious. Significant lattice corrugation is found in both MoTe2 (0.30Å) and MoS2 (0.77Å) layers. The interlayer Moiré potential, defined as the LPPM difference between the Mo atomic planes, has a depth of 0.20 eV and changes in direct correlation to the band gap variation in the Moiré cell, which has an amplitude of 0.04 eV. Wrinkling of the MoTe_{2}/MoS_{2} bilayer enhances the spatial variation of the local band gap by 5 meV; by contrast, its influence on the global band gap is within 1 meV. 

C71.00296: Simultaneous Prediction of the Magnetic and Crystal Structure of Materials Phil Hasnip, Ed Higgins, Matt I. J. Probert The coupling between magnetic properties and crystal structure in many magnetic materials means that it is essential to take a holistic approach to predicting their structure. We present for the first time a genetic algorithm that performs a simultaneous global optimisation of both magnetic structure and crystal structure, and illustrate its utility in a range of systems including a complex interface structure between a halfmetallic Heusler alloy and a semiconductor substrate. 

C71.00297: Minimization studies of elemental carbon using LCBOP semiempirical potential. Philip Chrostoski, Chathuri Silva, Philip Fraundorf Elemental carbon is interesting to study thanks to its material properties and structural diversity, which ranges from nanotubes through graphite to diamond. In our study of slowcooled carbon droplets condensed in coolstar atmospheres, computational study with semiempirical potentials is complementary to experiment and ab initio work. We’ve used the longrange carbon bondorder potential to relax, via conjugate gradient, 1.8 g/cc liquidlike carbon tiledcube and isolatedcluster systems with 13, 20 and 100 atoms, as well as tetrahedral nanodiamond clusters of 17, 22 and 29 atoms. Tiledcube simulation nearest neighbor histograms show a bond defining gap between 1.72.0 Å. Coordination statistics then show a high percentage of sp and sp2 coordination. Ring sizes of 5  7 atoms form more prominently than others, with 5 and 6 atom rings especially abundant. Isolated cluster relaxations show a high amount of sp chains forming, and less ring formation than the tiledcube simulations. We also see a volume increase for the isolated clusters, unlike comparable density functional theory (DFT) simulations. Our isolated diamondcluster relaxations saw less surface reconstruction than with DFT. 

C71.00298: Line integral approach for fiberfiber interactions implemented in LAMMPS Anirban Pal Fiber networks are currently modelled using discrete beadspring type molecular models or cylindrical discreteelement (DEM) models. Beadspring models often suffer from issues arising from artificial friction originating at the beadbead contacts, and DEMtype models suffer from high computational demands. Thus, there is a need for better models. Here, the cohesive interaction energy between straight fibers is expressed as a double integral. This double integral can be converted into a single integral that has two terms in its integrand: g(r), which depends on the relative geometrical positioning of the fibers, and V(r), which reflects the interaction energy. Although V(r) is readily available in analytical form, (can be of the lennardjones type), g(r), which is essentially a distance distribution function of pointpairs located across 2 fibers, requires computation. The method to compute g(r) involves elliptic integrals and is computationally demonstrated in this work. An implementation of the resulting fiberfiber interaction is demonstrated in LAMMPS, a popular molecular dynamics package, and its computational and scientific performance is evaluated. 

C71.00299: First Principles Evaluations of the SpinOrbit Couplings in Crystals Kensuke Kurita, Takashi Koretsume The spinorbit coupling (SOC) plays a crucial role in many spinrelated phenomena such as anomalous Hall effect and spin Hall effect. However, the strength of the SOC in solids and its relation to the isolated limit have not been well understood. Here, we quantify the atomic SOC in solids by constructing the tightbinding Hamiltonian from the Wannier functions obtained by the firstprinciples calculation. By calculating the atomic SOC in monatomic crystals and binary compounds systematically, we find that the strength of the atomic SOC is not the atomspecific property but depends much on the crystal structure and chemical composition. We show that its crystal dependence is well explained by the spread of the Wannier function. 

C71.00300: Timeevolution of a Schrödinger electron driven by a localized oscillating potential Liubov Zhemchuzhna, Godfrey Gumbs, M. Lawrence Glasser, Andrii Iurov, Danhong Huang We have obtained a semianalytical solution of the Schrödinger equation for a massive particle in the presence of a harmonic timedependent ∼ cos (ω t) singlepoint ∼ δ(x) potential. We present a detailed analysis for determining the dependence of the wave function on the amplitude and frequency of the oscillatory potential, and the chosen initial conditions for the particle wave function. We have considered separately when either the potential is negative and leads to a bound state or ispositive thus yielding scattering. Our derived results could be interpreted as being related to the dynamics of an electronic Floquet state subjected to a localized laserinduced dressing field. 

C71.00301: Theory of phonon glass behaviour in hostguest thermoelectrics with avoided crossing Bingyu Cui, matteo baggioli, Alessio Zaccone An analytical model is developed to describe the phonon dispersion relations of thermoelectrics with the presence of heavy guest atoms (rattlers). The model also accounts for anharmonic effects in phonon damping. The spectrum of low energy states contains acousticlike and (soft) opticallike modes, which display the typical avoided crossing, and which can be derived analytically by considering the dynamical coupling between host lattice and guest rattlers. Inclusion of anharmonic damping in the model allows us, for the first time, to compute the vibrational density of states (VDOS) and the specific heat, unveiling the anomalous boson peak (BP) relating to the glassy behaviour of phonons in the otherwise crystalline material. We discuss the dynamics of the BP as a function of the strength of the interaction between the soft modes and the anharmonic lattice, and of the energy gap between the two avoidedcrossing branches. Moreover, we find a robust linear correlation between the BP frequency and the energy of the soft opticallike modes. 

C71.00302: Giant effect of spinlattice coupling on the thermal transport in twodimensional ferromagnetic CrI_{3} Guangzhao Qin, Zhenzhen Qin, Huimin Wang, Ming Hu Recently, twodimensional monolayer chromium triiodide (CrI3) with intrinsic magnetism was discovered, which shows promising applications in many technologies from sensing to data storage where thermal transport play a key role. So far the effect of spinlattice coupling on the thermal transport properties has not been explored yet. In this talk, I would like to present the giant effect of spinlattice coupling on the thermal conductivity of monolayer CrI3. The thermal conductivity is more than two orders of magnitude enhanced by the spinlattice coupling. The effect is found to be especially stronger for the acoustic phonon modes, which dominates thermal transport with spinlattice coupling. Deep analysis shows that the reason lies in the weakened phonon anharmonicity by spinlattice coupling. The bond angle and atomic position are changed due to the spinlattice coupling, making the structure more stiff and more symmetric, which lead to the weaker phonon anharmonicity, and thus the enhanced thermal conductivity. This study uncovers the giant effect of spinlattice coupling on the thermal transport, which would deepen our understanding on thermal transport and shed light on future research of thermal transport in magnetic materials. 

C71.00303: Resonantly enhanced polariton wave mixing and Floquet parametric instability Sho Sugiura, Mikhail Lukin, Eugene Demler, Daniel Podolsky Recent experiments by Cartella et al. [1] demonstrated terahertz optical amplification in SiC insulator following a strong midIR pump that resonantly excited the SiC stretching mode. Motivated by these experiments we study the problem of light reflection from a slab of insulating material with a strongly excited polariton mode. We introduce a new theoretical approach for analyzing this system using the Floquet formalism, in which polariton oscillations provide periodic time modulation. We present an analytic solution of the Fresnel light reflection problem. We demonstrate discontinuous dependence of the reflection coefficient on the incoming photon frequency, which we attribute to the existence of unstable polariton modes. We interpret these instabilities as resonantly enhanced polariton parametric wave mixing. Our results provide a simple physical interpretation of light amplification observed in recent experiments by Cartella et. al. [1]. Moreover, we argue that Floquet parametric instability could already be present in these experiments. Our approach utilizing the Floquet formalism is applicable to a broad class of systems. 

C71.00304: Response at finite temperature Olle Hellman We present recent developments using the temperature dependent effective potential technique (TDEP) to model strongly nonharmonic materials. The method employs model Hamiltonians that explicitly depend on temperature. I will present applications pertaining to thermal conductivity, inelastic neutron spectra and phase stabilities. In addition, we investigate the crossterms between anharmonicity and nonadiabatic electronphonon coupling and its influence on transport properties. 

C71.00305: Deep Spectral Coarse Graining: Learning Simple, Dynamically Consistent Protein Models Nicholas Charron, Feliks Nüske, Jiang Wang, Lorenzo Boninsegna, Ankit Patel, Cecilia Clementi Coarse grain models of proteins offer promising gains in both computational efficiency for molecular simulations and the development of simple physical interpretations. Recent efforts have focused on formulating the development of coarse grained force fields as a supervised learning problem, taking advantage of deep learning techniques for handling highly nonlinear multibody effects produced by imposing coarse grained representations. In this work, we present a deep learning method that utilizes spectral information from simulation data to preserve essential dynamics of the original system. Following a Koopmanmotivated approach, we optimize the dynamical consistency between fine grain and coarse grain systems by forming a cost from the dynamical generator eigenequation. Through this method, we can recover coarse grain empirical free energy landscapes that preserve essential dynamical information from the fine grain system. 

C71.00306: Crystalin Protine Structure Prediction Algorithm Danae Stephens The acurate prediction of protine structures is a continusly ongoing process, with the traditinal methood beign a two step process of creating restraints and constructing a basic structre from that. Recent advancements in Machien Learnign and Nural Networkds have prvided new avenus to increase acuracy for these predicted protien structures. By utilizing a Nural Network to estimat moleculare distances, and runing basic torsion angle predictions, enables us to more acuaratle fold protines and create acurate protien structure predictions for use. Hopefuly this nural network will allow further reaserch an dutilization of protines that we are curently are unable crystalize and study by traditinal means. 

C71.00307: Constructing the Neural Network Potential With the Energies of the Atom and Its Derivatives Jisu Jung, Wonseok Jeong, Seungwu Han Neural Network Potentials (NNPs) are highly anticipated as a possible breakthrough to overcome the tradeoff between accuracy and speed in atomistic simulations. NNP learns the potential energy surface from the reference first principle calculations. The most widely used first principle calculation is based on the density functional theory (DFT) with the planewave basis, which does not provide atomic energy. Thus it is not possible to directly train the NNP to learn target atomic energy from planewave DFT. To overcome this limitation Behler and Parrinello designed highdimensional NNP such that it represents the atomic energy as the sum of total energy. 

C71.00308: Grain boundary structures of elemental metals using machine learning potential Takayuki Nishiyama, Atsuto Seko, Isao Tanaka Global optimization algorithms, such as multistart local optimizations and Bayesian optimization, have been useful to determine the microscopic structure and its grain boundary energy for a given macroscopic grain boundary model. Together with the global optimization algorithms, the density functional theory calculation and interatomic potentials have been employed to estimate the grain boundary energy. However, the former is computationally demanding, and the latter often lacks the predictive power for a variety of grain boundary structures. Recently, several machinelearning potentials have been proposed, which are expected to enable computing the grain boundary energy accurately with less computational costs. In this study, we investigate symmetric tilt grain boundary structures and their grain boundary energy surfaces in elemental metals using a combination of global optimization algorithms and linearized machine learning potentials [1]. We compare the grain boundary structures and grain boundary energy surfaces obtained from machine learning potentials and embedded atom method potentials to examine the accuracy and stability of our procedure. 

C71.00309: Machine LearningAided Development of Empirical ForceFields for Glasses Mathieu Bauchy The development of reliable, yet computationally efficient interatomic forcefields is key to facilitate the modeling of glasses. However, the parametrization of novel forcefields is challenging as the high number of parameters renders traditional optimization methods inefficient or subject to bias. Here, we present a new parameterization method based on machine learning, which combines ab initio molecular dynamics simulations, Gaussian Process Regression, and Bayesian optimization. By taking the examples of silicate and chalcogenide glasses, we show that our method yields new interatomic forcefields that offer an unprecedented agreement with ab initio simulations. This method offers a new route to efficiently parametrize new interatomic forcefields for disordered solids in a nonbiased fashion. 

C71.00310: A theoretical study on crystallization of chalcogenides via neural network potential Dongheon Lee, Kyeongpung Lee, Dongsun Yoo, Wonseok Jeong, Kyuhyun Lee, Seungwu Han Phasechange materials (PCM) have attracted wide interests in fields such as data storage and neuromorphic computing. GeSbTe alloys are a representative PCM, which show large contrast of optical and electrical properties between crystalline and amorphous phases. Atomic scale modeling of PCM has relied on abinitio molecular dynamics (AIMD), but its large computational costs have limited simulation size and time. Neural network potential (NNP) can deal with more than thousands of atoms upto microseconds, while accurate potential energy surface can be obtained by learning the data of density functional theory (DFT). 

C71.00311: Direct prediction of quantum accurate forces for multicomponent systems Subodh Tiwari, Pankaj Rajak, Kenichi Nomura, Aiichiro Nakano, Fuyuki Shimojo, Rajiv Kalia, Priya Vashishta Phasechange materials (PCM) are routinely exploited in optical data storage, flexible devices and neuromorphic computing due to the extreme electrooptical contrast between crystalline and amorphous states. However, highquality forcefield models for moleculardynamics (MD) simulations of PCM are not available, while quantum molecular dynamics simulation is limited by the small size of system. We have developed neuralnetwork (NN) force fields for GeTe and Ge_{2}Sb_{2}Te_{5}, which are trained using atomic forces computed by density functional theory. Radial and angular feature vectors are designed and trained, which feature permutational and translational invariance and rotational covariance of forces. The accuracy of the NN force fields is validated by performing MD simulation involving up to 100,000 atoms and computing multiple structural and dynamical properties. 

C71.00312: IFFR Models to Accurately Simulate StressStrain and Failure Porperties of Carbon Allotropes and Polymer Composites Jordan Winetrout, Krishan Kanhaiya, Ravindra Pandey, Gregory M. Odegard, Hendrik Heinz Stress induced mechanical failure of polymeric materials is a result of the breakage of covalent bonds. The occurrence of bond breakage and formation is only observed during reactions. This study focuses on the novel bondbreaking capabilities of the Interface Forcefield (IFFR). Traditional IFF models simulated systems using harmonic potentials. The IFFR model incorporates Morse potentials; thereby, eliminating the restoring force experienced by bonded atoms stretched at large distances. This enables accurate predictions of mechanical responses in a variety of periodic systems. This study shows moduli and strength predictions of a singlewalled carbon nanotube, poly(acrylonitrile) crystal, cellulose β crystal, and steel FCC lattice to be comparable to experimental values. Mechanical property predictions using IFFR models are realized magnitudes faster than reactive forcefield (ReaxFF). 

C71.00313: Enhanced Optical Properties of SingleWalled Carbon Nanotubes (via SP^{3}Hybridization Defects) from ManyBody Perturbation Theory Based on Density Functional Theory Calculations Braden Weight, Andrei Kryjevski The optical consequences of functionalized carbon nanotubes (CNTs) (via a pair of SP^{3}hybridized functional groups attached to a carbon ring) have been explored in great depth due to their promise of superior electronic properties for tunable emission in infrared energies. These studies have relied on timedependent density functional theory (TDDFT) calculations to model the excited states of these particles, but very little work has been completed on multiple exciton generation (MEG) processes within these systems. Here we employ a novel method based in nonequilibrium, finitetemperature, manybody perturbation theory (MBPT) calculations that utilize output from density functional theory (DFT) to accurately model excited states of these systems. We solve the Boltzmann transport equation (BE), including phonon absorption/emission and biexciton formation/recombination terms [1,2]. With this approach we compute an array of CNTs of varying chirality and functionalization scheme. We see that SP^{3}defect functionalization of pristine CNTs that had highenergy biexciton MEG thresholds (E ≈ 2.4E_{g}) can be reduced to 2E_{g}, which drastically increases their value as efficient multiple exciton sources. 

C71.00314: QuasiDiabatic Scheme for Nonadiabatic Onthefly Simulations Wanghuai Zhou, Arkajit Mandal, Pengfei Huo We use the quasidiabatic (QD) propagation scheme to perform onthefly nonadiabatic simulations of the photodynamics of ethylene. The QD scheme enables a seamless interface between accurate diabaticbased quantum dynamics approaches and adiabatic electronic structure calculations, explicitly avoiding any efforts to construct global diabatic states or reformulate the diabatic dynamics approach to the adiabatic representation. Using diabatic dynamics methods, the QD propagation scheme enables direct nonadiabatic simulation with complete active space selfconsistent field onthefly electronic structure calculations. The population dynamics obtained from both approaches are in a close agreement with the quantum wavepacket based method and outperform the widely used trajectory surface hopping approach. Further analysis of the ethylene photodeactivation pathways demonstrates the correct predictions of competing processes of nonradiative relaxation mechanism through various conical intersections. This work provides the foundation of using accurate diabatic dynamics approaches and onthefly adiabatic electronic structure information to perform abinitio nonadiabatic simulation. 

C71.00315: Abstract Withdrawn


C71.00316: Dielectric Screening by 2D Substrates Keian Noori, Nicholas Cheng, Fengyuan Xuan, Su Ying Quek While electronic screening within 2D materials has been studied extensively, the question of how 2D substrates screen charge perturbations or electronic excitations adjacent to them still remains. 

C71.00317: Universal metric for plasmonicity of excitations at the nanoscale Luca Bursi, Runmin Zhang, Kyle D. Chapkin, Naomi J. Halas, Peter J. Nordlander A promising trend in plasmonics involves shrinking the size of plasmonsupporting structures down to a few nanometers, thus enabling control over light−matter interaction at extremesubwavelength scales. In this limit, quantum mechanical effects, such as nonlocal screening and size quantization, strongly affect the plasmonic response, rendering it substantially different from classical predictions. For very small clusters and molecules, collective plasmonic modes are hard to distinguish from other excitations, such as singleelectrons ones. Using rigorous quantum mechanical computational techniques for a wide variety of physical systems, we describe how the plasmonic character of a nanostructure’s optical resonance can be quantified. We define a universal metric, the generalized plasmonicity index (GPI), which can be straightforwardly implemented in any computational electronicstructure or classical electromagnetic approach to discriminate plasmons from singleparticle excitations and photonic modes [ACS Nano, 11, 7321 (2017); PNAS, 115, 9134 (2018)]. The GPI metric deepens our fundamental understanding of what is a plasmon down to the molecular limit of plasmonsupporting nanostructures and provides a rigorous foundation for further development in molecular plasmonics. 

C71.00318: Particleincell simulation of plasmons Wen Jun Ding, Jeremy Lim, Do Thi Bich Hue, Xiong Xiao, Michel Bosman, Lay Kee Ang, Lin Wu Plasmons are collective oscillations of the free electron gas density in conducting media such as metals. In many cases of interest, plasmons are typically characterized by solving the Maxwell equations, where the electromagnetic response can be described by the bulk permittivity. Motivated by the physical similarity of plasmas and oscillating conduction electrons, we present a particleincellbased method of simulating plasmons. By solving for the instantaneous particle position and momentum, which are connected to the electromagnetic fields through current, we demonstrate the capability of this novel approach in elucidating information on the formation of the plasmons. Specifically, we demonstrate plasmon formation in gold nanorods through laser irradiation and singleelectron excitation. Lastly we investigate the nonlocal effects of ultrasmall nanoparticles approaching quantum limit. 

C71.00319: Heat transport between two critical onedimensional systems Sonja Fischer, Lars Fritz, Dirk Schuricht Heat transport can reveal information about interacting manybody systems beyond other transport probes. In particular, in one dimension it has been shown that the energy current is directly proportional to the central charge, thus revealing information about the degrees of freedom of critical systems. In this work, we explicitly verify this result in two cases for translationally invariant systems based on explicit microscopic calculations. More importantly, we generalise the result to nontranslation invariant setups and use this to study a composite system of two subsystems possessing different central charges. We find a bottleneck effect meaning the smaller central charge limits the energy transport. 

C71.00320: Thermal conductivity prediction from basic properties using a developed artificial neural network Guangzhao Qin, Huimin Wang, Zhenzhen Qin, Ming Hu Highthroughput screening and material informatics have shown a great power in material discovery including Libattery materials, alloys, photocatalysts, and nanowires. In this talk, we will present the accurate thermal conductivity prediction from machine learning technique using a developed artificial neural network (ANN). With 231 datasets of the basic properties describing materials calculated from firstprinciples and the corresponding thermal conductivity from experimental measurements as training data, the constructed ANN is well trained by iterating to reduce the loss function. The trained ANN model for thermal transport successfully captures the general correlation between basic properties and thermal conductivity for different types of materials, which is predictive spanning 4 orders of magnitude of the thermal conductivity. The developed ANN model in our work for fast and accurately predicting thermal conductivity provides a powerful tool for the largescale thermal material screening with targeted thermal transport property. 

C71.00321: Exploring structure and magnetism of collapsed lanthanides Evgeny Plekhanov, Cedric Weber By using DFT within VASP [1] and DFT+DMFT within CASTEP codes [2], we study the collapsed phases of Tb, Gd, Dy, Sm, Nd and Y at extreme pressure up to 240GPa. 

C71.00322: DFT studies of graphene in carbon droplets condensed in stellar atmospheres Chathuri Silva, Philip Fraundorf, Eric Majzoub, Philip Chrostoski Elemental carbon at low (ambient) pressure sublimates to vapor near 4000K, but liquid carbon is reported after laser ablation. Some meteoritic carbon particles, formed in red giant atmospheres, show a “graphenecore”/graphiterim structure likely from supercooled carbon droplets that nucleated graphene sheets on randomlyoriented 5member rings. Similar corerim particles form by slow cooling of carbon vapor in the lab (HAL02238804). Our computations target growth of carbon rings & graphene sheets at the experimental 1.8 g/cc density estimate, by relaxing random liquidlike configurations of 13/20atom clusters in a supercell. Interatom distances characteristic of covalent vs. metallic interactions (with a gap in 1.72 Å range) allow us to identify covalent “bonds” with small separation. Local energy minima at T = 0K show sp^{2} & sp coordination numbers, as in the literature. Ring sizes vary from triangle to heptagon, but pentagons are more abundant than hexagons, also consistent with previous reports. Work remains to see if pentloops can nucleate the growth of faceted pentacones, as suggested by HRTEM imaging. Unlayered graphene sheets in a frozen matrix may be an effective diffusion barrier. 

C71.00323: Abstract Withdrawn


C71.00324: Dark Matter and Baryons (Surplus Quarks) Generated by Nonequilibrium Confinement of Quarks Leif Matsson The emergence of baryons (surplus quarks ) at Big Bang, required a nonequilibrium binding and superconductorlike condensation of quarkantiquark pairs before the electroweak (EW) symmetry breakdown. (Similar for leptons). As will be further shown, the formerly unknown dimensionless coupling to the GinsburgLandau like potential and the scale parameter in the EW theory then become microscopic functions of the massive quark and antiquark fields, thus defining the matterantimatter asymmetry and the dark matter content in the Universe at correct orders of magnitude. The number of free parameters in the Standard Model has thereby been reduceed. 

C71.00325: Effect of Surface Defects on FieldInduced HotCarrier Chemistry in Dielectric Polymers Subodh Tiwari, Thomas Linker, Hiroyuki Kumazoe, Fuyuki Shimojo, Rajiv Kalia, Aiichiro Nakano, Priya Vashishta Performance of dielectric polymers under high electric field is limited by the electrical breakdown, which is commonly understood as an avalanche of processes such as carrier multiplication and defect generation. We model the hotcarriers transport in dielectric polymer, polyethylene, with excitedstate quantum molecular dynamics simulations in presence of electric field, which reveal multiple microscopic processes induced by hot electrons and holes under an electric field. The key chemical damage occurs due to localization of holes at the surface of slab which weaken carboncarbon bonds on the surface. Introducing surface defects alter the valencaband maximum (VBM) state in polyethylene leading to bond breaking at lower field. Further, we have isolated CC bond lengths and VBM localization as a proxy for dielectric breakdown. Such proxies allow us to perform one simulation to understand the effect of defect rather than scanning the complete electric field range. Such quantitative and qualitative information can be incorporated into first principlesinformed, predictive modeling of dielectric breakdown. 

C71.00326: Simulation of the effect of electric field on the performance of ion separation and water desalination using a graphenecarbon nanotube membrane Samaneh Rikhtehgaran, Luc T Wille Using molecular dynamics (MD) simulations, a graphenecarbon nanotube membrane is exposed to external electric field with intensities E = 0.1, 1, 10, and 100 mV/Å in order to separate Na^{+ }and Cl^{ }ions from a salt water solution to produce fresh water. The results show that by increasing the strength of the applied electric field, the ion separation will be increased to 100% for E = 100 mV/Å. It is found that the ion separation efficiency of this filter is already greater than 90% for E = 10 mV/Å. Based on the results of this study, it is suggested that the graphenecarbon nanotube membrane can be used as a device of water desalination under the application of electric field. 

C71.00327: Effects of surface transition and adsorption on ionic liquid capacitors Huikuan Chao, ZhenGang Wang Room temperature Ionic liquids (RTILs) are a type of synthesized electrolytes possessing superb electrochemical stability and low vapor pressure compared with conventional aqueousbased electrolytes, which offers significantly enlarged electrochemical window and ease of maintenance for capacitors. Experiments measuring capacitance in concentrated RTILs often found hysteresis indicating that an underlying phase transition might exist. Current theories explaining the hysteresis in terms of phase transition either assume RTIL mixtures with neutral solvents or omit ionion correlations in RTILs. In this study, a variant of an existing RTIL model [1] is established for solventfree RTIL capacitors incorporating both ionion correlations and nonelectrostatic interactions. We first use the model to explore the spontaneous charge separation in the capacitors and find that this transition is a common feature for realistic choices of the model parameters for most RTILs. Next, we investigate the effects of preferential ion adsorption on this charge separation transition. The results show that preferential ion adsorption can be a useful design parameter for optimizing the energy storage of the capacitors. 

C71.00328: Disintegration of Surfactant Micelles at MetalWater Interfaces Promotes their Strong Adsorption Sumit Sharma, Himanshu Singh We have studied adsorption behavior of surfactant micelles at metalwater interfaces via fully atomistic simulations. We show that micelles experience a free energy barrier to adsorption. Near the metal surface, surfactant molecules in the micelles slowly rearrange leading to complete disintegration of the micelles. Disintegration of the micelles results in much stronger adsorption. After the disintegration, surfactant molecules adsorb by lying flat on the metal surface. By simulating adsorption of micelles treated as rigid bodies, we show that when the micelles remain intact, they have a weak tendency to adsorb. 

C71.00329: Targeted Synthesis Conditions of Layered Bismuth Oxychalcogenides Via Electrochemical Phase Diagrams Lauren Walters, Chi Zhang, James Rondinelli We investigated how density functional theory calculations of electrochemical stability can guide the experimental hydrothermal synthesis of bismuth oxychalcogenides. The target phases, which are layered thermoelectrics and exhibit electronic anisotropy, represent exciting materials for catalysis, photoluminescence, and energy applications. We coupled experimental synthesis with DFTcalculated multielement Pourbaix diagrams to identify target pH and potential synthesis regions that ultimately proved successful. We further investigated numerous degrees of freedom present in the reaction, such as mass ratio of reactants, temperature, and concentration of ions, to qualitatively understand how changes in the chemistry of the oxychalcogenides alter phase stability. Last we discuss how these materials can be driven towards target phase production. 

C71.00330: Resolution of the identity approximation applied to PNOF family of correlation calculations Juan Felipe Huan Lew Yee, Mario Piris, Jorge M. del Campo Ramírez PNOFi (i = 17) family of functionals deal with electronic structure correlation calculations by means of the reduced electron density matrix approach (1RDM). The major advantage of a 1RDM formulation is that the unknown functional only needs to incorporate electron correlation. PNOFi family of functionals provide an efficient way of including dynamic and static correlation as compared to wave function methods. However, a transformation from atomic orbital integrals to molecular orbital integrals has to be performed in order to computate the Coulomb and Exchange matrices in molecular orbital representation J^{OM} and K^{OM} respectively, which involves an overall fifth power time scaling factor. 

C71.00331: Coherent states, Gram matrix, and Hofstadter butterfly with flat band Youjiang Xu, Han Pu A method to construct flat band model is exhibited. If a Gram matrix built upon a set of vectors is regarded as a Hamiltonian of certain physical system, then we can control the ground state degeneracy by modifying the vectors. If the vectors are chosen to be certain subsets of coherent states, the resulting Hamiltonians describe singleparticle lattice models with a gauge field. The massive degeneracy of the lowest band in these models is a universal property independent from the shape of lattice, which is controled by the completeness of the subsets of coherent states. The excitation spectrums show Hofstadterbutterflylike patterns which vary when the lattice changes. The models also feature ground state wave functions in universal form, which is like Landau lowest levels, but the dynamics differs. Experimental realization of the models is promising. 

C71.00332: Computational simulation of patterns in a reactiondiffusion model Monica Velasco, Cesar Minolli, John Prias Recent studies in reactiondiffusion models has been oriented to produce patterns for studying polycrystalline materials as graphene oxide and among others, here in show optimized algorithm for obtaining patterns of a reactiondiffusion equation. The optimization of algorithm were carried out by using fortran code and the respective visualization was employing the Visit software. The results suggest that is possible to obtain theoretical patterns of reactiondiffusion equation as expected, which could be comparable with the experimental patterns of high resolution transmission electron microscopy (HRTEM) in graphite oxide samples. 

C71.00333: FiniteTemperature Correlation Functions Using the Quantum Minimally Entangled Typical Thermal States Algorithm ShiNing Sun, Adrian Tan, Mario Motta, Fernando Brandão, Garnet Chan, Austin Minnich Finitetemperature correlation functions provide fundamental information about the excitations and response properties of quantum manybody systems. Recently, the quantum minimally entangled typical thermal states (QMETTS) algorithm was introduced for calculating thermal averages of certain observables on nearterm quantum devices. However, due to the computational cost of the quantum imaginary time evolution (QITE) subroutine underlying the QMETTS algorithm, the calculation of general thermal quantities with QMETTS remains challenging. Here, we report the calculation of finitetemperature correlation functions of quantum spin models with QMETTS. We describe how to reduce the cost of calculations by exploiting Hamiltonian symmetries and other constraints to eliminate qubits and reduce measurements. Our work advances efforts to study finitetemperature properties of quantum manybody systems on quantum computers. 

C71.00334: Electrosatic screening, dynamics and structure of [BMIM+][BF4] and [BMIM+][PF6] with confinement Suehyun Park, Jesse G. McDaniel Ionic liquids are spotlighted as electrolytes for batteries and supercapacitors. Such applications have nanoconfined systems, where deviation of electrostatic screening, dynamics, and structure of ionic liquids from bulk properties is caused. Although electrostatic screening is a fundamental interaction for any charged particles, electrostatic screening condition for ionic liquids is not discovered yet in confined systems. To fully utilize ionic liquids in electronic devices, it should be fully revealed how confinement alters physical properties of ionic liquids. Here, we conducted molecular dynamics simulations of [BMIM+][BF4] and [BMIM+][PF6] between two graphene sheets with gap of 1.5 to 4.5 nm. Confined ionic liquids show slower dynamics by 2 orders of magnitude compared to bulk dynamics and have nonmonotonic behavior in dynamics. In addition to dynamics, we observed that capacitance is independent of confinement length. To explain this confinement effect, we computed electrostatic screening condition derived from StillingerLovett sum rules. Furthermore, we investigated polarization effect on electrolytes and electrodes in confined system. 

C71.00335: Finitetemperature auxiliaryfield Quantum Monte Carlo study of dynamical correlation functions in correlated fermion systems Hao Shi, YuanYao He, Shiwei Zhang We compute dynamical (imaginarytime) correlation functions in correlated fermion systems using the finitetemperature auxiliaryfield Quantum Monte Carlo method. The sign problem is eliminated by introducing constraints in auxiliaryfield space. We carry out a systematic benchmark study of dynamical correlation functions in the twodimensional repulsive Hubbard model, for various interaction strengths, density, and temperatures. At high temperatures, essentially exact results are obtained independent of the form of the constraint, similar to calculations of static quantities [1]. With decreasing temperature, we discuss how the constraint can be optimized to improve the accuracy of dynamical correlation functions. In the context of studying the pseudogap behavior, we apply the method to compute the selfenergy and spectral functions in the Hubbard model. 

C71.00336: Lowenergy physics in the critical phase of the bilinearbiquadratic spin1 chain Moritz Binder, Thomas Barthel We use an efficient density matrix renormalization group (DMRG) algorithm to compute precise dynamic structure factors for the bilinearbiquadratic spin1 chain with Hamiltonian H = Σ_{i} [cosθ (S_{i} * S_{i+1}) + sinθ (S_{i} * S_{i+1})^{2}]. Here, we focus on explaining the physics in the extended critical phase (π/4 ≤ θ < π/2) of the model. The phase transition from the Haldane phase to the critical phase is marked by the SU(3)symmetric ULS point (θ = π/4), where the elementary excitations are spinons that can be obtained from the Bethe ansatz solution. As we move deeper into the critical phase, the spinon continua contract, and new striking features appear at higher energies. In the vicinity of the transition point from the critical to the ferromagnetic phase, a dispersion with a surprisingly simple functional form emerges, suggesting integrability of the model in the limit θ → π/2^{}. 

C71.00337: Entanglement decomposition for the simulation of quantum manybody dynamics Thomas Barthel Nonequilibrium dynamics in quantum matter are at the frontier of current research. Efficient and precise simulation techniques are needed to improve our understanding of equilibration and thermalization, dynamical phase transitions, decoherence effects, quantum transport etc. A major obstacle is the growth of entanglement with time which generally implies an increased complexity of the quantum state. For instance, the computation costs of simulations based on tensor network states generally grow rapidly in time, limiting the maximum reachable times. I will show how this problem can be addressed through entanglement decomposition. We can follow the dynamics, starting from an initial state, until the entanglement has grown to a point where our simulation resources are exhausted. We then decompose the current state into lower entangled components and continue by simulating the evolution of these components, decomposing them again when needed. I will demonstrate a specific entanglement decomposition scheme for matrix product state simulations and discuss its efficiency for the study of dynamics in quantum magnets. 

C71.00338: Counterdiabatic Spin Squeezing Zeyang Li, Boris Braverman, Enrique Mendez, Vladan Vuletic Spin squeezing states (SSS) are atomic entangled states that can be used to enhance the atomic precision measurements beyond the standard quantum limit. Existing implementations relying on unitary evolution are primarily based on oneaxis twisting induced through coherent cavity feedback. By adding an auxiliary driving Rabi field, our work can generalize this oneaxis twisting to an equivalent twoaxis twisting, which features robustness against technical imperfections, as well as the potential to reach higher squeezing and therefore greater metrological gain. Moreover, by optimizing the timevarying auxiliary field, we obtain a fast preparation of SSS with high metrological gain, which we call as counterdiabatic spin squeezing. 

C71.00339: Quantum ManyBody Effects in Optical Kerr Media Giulia Marcucci, Davide Pierangeli, Claudio Conti Nonlinear quantum optics is emerging as one of the most important research directions in photonics. These include quantum solitons (QSs), and highly nonclassical supercontinuum generation (SCG). We need new strategies to design nonlinear optical devices operating at low photon numbers and theory to describe how they work. 

C71.00340: Bosonic entanglement crossover from groundstate scaling to volume laws Qiang Miao, Thomas Barthel The crossover behavior of eigenstate entanglement entropies from an area law or logarea law for low energies and small subsystem sizes to volume laws for high energies and large subsystems can be described by scaling functions. We demonstrate this for two bosonic systems. The harmonic lattice model describes a system of coupled harmonic oscillators and is a lattice regularization for free scalar field theories. For dimensions d ≥ 2, the ground state of this model displays an entanglement area law, even at criticality, because excitation energies vanish only at a single point in momentum space. In contrast, Bose metals feature a finite Bose surface with zero excitation energy. One hence finds logarea laws for the groundstate entanglement. For both models, we sample excited states. The distributions of their entanglement entropies are sharply peaked around subsystem entropies of corresponding thermodynamic ensembles in accordance with the eigenstate thermalization hypothesis. In this way, we determine the scaling functions numerically. Eigenstates for quasifree bosonic systems are not Gaussian. We resolve this problem by considering appropriate squeezed states instead, for which entanglement entropies can be evaluated efficiently. 

C71.00341: A New Graphical Method for Designing Exactly Solvable Models Masahiro Ogura Exactly solvable lattice spin models have played important roles in physics. Since Onsager’s work, some lattice spin models were exactly solved by treated as free fermion models (FFMs). For example, the onedimensional XY model, the onedimensional transverse field Ising model, and the Kitaev’s twodimensional honeycomb lattice model (KHLM) can be solved in this way ([1],[2]). 

C71.00342: Application of the Recursive Projection Method to Electronic Structure Calculation Shoham Sen, Yang Wang, Timothy Breitzman, Kaushik Dayal In this work, we focus on the mixing scheme used during the SelfConsistent (SC) process of solving the KohnSham (KS) equations. The two most common mixing schemes used in practice are the “Simple Mixing” and the “Modified Broyden Mixing”, the former is a fixed point method while the latter is a QuasiNewton method. A characterization of the former method is that it takes less computation time per iteration but required a lot of iterations to converge; the latter gives quadratic convergence hence fewer iteration but takes more computational time per iteration. It can be shown that Simple Mixing converges if the eigenvalues of the Jacobian lie within some ellipse. Thus even if only a few eigenvalues lie outside the ellipse, Simple Mixing will not converge. We proposed the “Recursive Projection Method” (RPM) modified for electronic structure calculation, where we estimate the subspace spanned by the eigenvectors whose eigenvalues lie within the ellipse, call this the “stablesubspace”. We perform Simple Mixing on the stablesubspace and Modified Broyden on the complementary subspace. We expect that this method will improve convergence for systems of large size. 

C71.00343: The Energy Landscape Governs Brittleness and Ductility in Glasses Longwen Tang, Mathieu Bauchy Based on their structure, noncrystalline phases can fail in a brittle or ductile fashion. However, the nature of the linkages between structure and propensity for ductility in disordered materials has remained elusive. Here, based on molecular dynamics simulations, we investigate the fracture of several disordered phases (metallic glass, glassy silica, colloidal gel, etc.) with varying degrees of disorder. We find that that, in general, structural disorder results in an increase in ductility. By applying the activationrelaxation technique (an accelerated sampling method to identify transition states), we show that the degree of plasticity is controlled by the topography of the energy landscape. 

C71.00344: Interface of Hydrated Perfluorosulfonic Acid Electrolyte with a Platinum Catalyst:
Structural Analyses with Dissipative Particle Dynamics Simulations Nobuo Tajima, Jun Nara, Taku Ozawa, Hiroya Nitta, Kosuke Ohata, Takahisa Ohno Dissipative particle dynamics (DPD) simulations were performed to study structures of hydrated perfluorosufuonic acids (PFSA) in contact with platinum surfaces. Two types of interfacial systems were simulated, where PFSA molecules interact with a cube and a slab of platinum, respectively representing a small catalyst particle used in a regular fuel cell and a platinum substrate popularly used in a model system experiment. The calculated results suggest that the two systems form a shell structure and a layer structure, respectively, of PFSA components near the platinum surfaces. The water component covers the platinum surfaces popularly in both systems, of which the coverage depends on the hydration levels of PFSA. Detailed analyses revealed that the water component networks are quite different in the two systems, which are threedimensionally connected in the systems with a platinum cube, while disrupted by hydrophobic components in the systems with a platinum slab. 

C71.00345: Universal properties of creep flow in amorphous solids Marko Popovic, Tom.W.J. de Geus, Alberto Rosso, Matthieu Wyart Amorphous solids, such as atomic glasses, colloidal suspensions, granular matter or foams, begin to deform plastically when exposed to external stress Σ. Steady state deformation rate ∂_{t}ε of these materials in absence of thermal fluctuations is usually described as ∂_{t}ε ∼ (Σ − Σ_{c})^{β} for stresses above critical stress Σ_{c} and vanishes below it, while in presence of thermal fluctuations flow persists below Σ_{c}, but is exponentially suppressed. The transient plastic deformation rate, called creep flow, is much less understood despite its importance in practical applications. Creep flow often displays a powerlaw decay in time ∂_{t}ε ∼ t^{−μ} after which it can either arrest or eventually yield at fluidisation time τ_{f}. In recent years various numerical values and/or laws have been suggested for the exponent μ and time τ_{f} in particular experimental or numerical studies. We propose that mechanism underlying creep flow is the same as that of the steady state flow, which allows us to predicts parameters μ and τ_{f} of creep flow in terms of the steady state flow parameters, both in athermal and thermally activated systems. We successfully tested all our predictions using different mesoscopic elastoplastic models of amorphous solids and found them to be consistent with published experimental results. 

C71.00346: SHOCK COMPRESSION OF CONDENSED MATTER


C71.00347: Effect of structural collapse on electron density distribution and magnetic properties of ThCr_{2}Si_{2}type pnictides Michael Shatruk, Vincent Yannello, Judith K Roth, Alexander A Yaroslavtsev, Andrei Rogalev, Vasile O Garlea The structural phase transitions in the ThCr_{2}Si_{2}type materials involve a gradual or abrupt (firstorder) collapse along the tetragonal c axis. Despite many examples of such transitions in the AT_{2}X_{2} structures, the direct experimental assessment of changes in the electron density redistribution between the A and [T_{2}X_{2}] layers upon the formation and breaking of the X–X bonding interactions is largely lacking. Earlier studies have revealed fascinating pressureinduced transitions in EuCo_{2}Pn_{2} (Pn = P, As) which are accompanied by the change in the Eu oxidation state and the transition from the localized (4f) magnetism to itinerant (3d) magnetism. In the present contribution, we demonstrate that the changes in the electron concentration in the [Co_{2}Pn_{2}] layer defy the formal electroncounting rules that are often used for Zintllike phases. Xray absorption measurements offer the direct insight into the changes in the Eu oxidation state and magnetism and the associated redistribution of the electron density in the [Co_{2}Pn_{2}] layer. Calculations of the band structure and analysis of chemical bonding have provided a satisfactory interpretation for the observed changes in the Xray absorption spectra. 

C71.00348: Combining theoretical and experimental methods to study some zircontype orthovanadates at high pressure. Alfonso MunozGonzalez, Placida RodríguezHernandez, Tomas Marqueño, Enrico Bandiello, Daniel Errandonea Many studies of zircontype orthovanadates under high pressure have been performed. Some of these experiments using methanolethanolwater as pressure transmission medium report a zircontomonazite phase transition. In this work, we will focus on the study of the zircontoscheelite phase transition of some orthovanadates, combining high pressure experimental hydrostatic studies and ab initio simulations. Our approach provides information on the structural, electronic, dynamical, and elastic properties of these compounds. From our simulations, we found that around the transition pressure the zircon phase becomes dynamically unstable due to the softening of one B_{1u} silent mode. Our study of the elastic constants and the analysis of the generalized mechanical stability criteria show a mechanical instability also appears near the transition pressure. We will also report on the new high pressure phase that appear after the zircontoscheelite transition. 

C71.00349: New developments in large volume static compression with in situ synchrotron xray diffraction at High Pressure Collaborative Access Team (HPCAT) at the Advanced Photon Source Rostislav Hrubiak, Guoyin Shen, Curtis KenneyBenson, Changyong Park, Arun Bommannavar, Yu Shu, Itaru Ohira, Yoshio Kono The integration of xray diffraction measurements with physical properties characterizations in a large volume cell provides a unique opportunity to investigate insitu correlation between the atomic structure and the macroscopic properties of matter at high pressure (P) and high temperature (T) conditions. The beamline 16BMB capable of near comprehensive largevolume sample characterization at high P and high T conditions in a ParisEdinburgh (PE) cell by using a multitude of insitu xraybased techniques. An overview of the currently supported techniques that are available to users, with emphasis on new developments, is presented. Available techniques include: doublestage PE for amorphous structural measurements above 100 GPa, ultrasonic echo, fluid viscosity, high PT synthesis, xray absorption density measurement, powder diffraction, phase contrast radiography, liquid (im)miscibility, and thermoelectric properties measurements. 

C71.00350: Pressure induced phase transitions in topological crystalline insulator SnTe and its comparison with semiconducting SnSe: Raman and Firstprinciples studies Sukanya Pal, Raagya Arora, Subhajit Roychowdhury, Luminita Harnagea, Saurabh Kumar, Sandhya Shenoy, D.V.S. Muthu, Kanishka Biswas, U.V. Waghmare, A K Sood We report Raman study of a topological crystalline insulator (TCI) SnTe and a normal semiconductor SnSe, as a function of pressure at room temperature along with firstprinciples density functional theory calculations. Under pressure, isostructural transition is observed in SnTe as revealed by the anomalous softening of the strongest Raman mode up to 1.5 GPa. Further, SnTe undergoes structural transitions at ~ 5.8, ~ 12 and ~ 18.3 GPa. The 5.8 GPa transition is associated with a structural transition from ambient cubic (Fm3m) to orthorhombic (Pnma) phase which is no longer a topological insulator. Above the transition pressure of 12 GPa another orthorhombic Pnma[GeS] phase is stabilized coexisting with Pnma phase. Above 18.3 GPa enthalpy calculations show a transition from orthorhombic Pnma to a more symmetric cubic (Pm 3m) structure. Our highpressure study of SnSe on the other hand reveals that it undergoes two phase transitions: one from the orthorhombic (Pnma) structure to orthorhombic (Cmcm) structure at ~ 6.2 GPa and the other at ~ 12.9 GPa in which the Cmcm phase undergoes a semimetal to metal transition. Density functional theory calculations capture the contrast in pressure dependent behaviour of topological crystalline insulator SnTe and a normal semiconductor SnSe. 

C71.00351: WITHDRAWN ABSTRACT


C71.00352: Study of thermal properties of HMX in molten TNT. Natalya Suvorova, David M Oschwald, Dennis K Remelius, Laura Smilowitz, Bryan Henson, Pamela Bowlan Octol composed of 70 wt% of HMX and 30 wt% of TNT is one of the melt cast explosives that is widely used in many military applications, namely for shaped charges. Due to the presence of low melt TNT component octol exhibits complex thermal behavior. At the temperature above TNT melt, octol forms liquidsolid system that with further heating undergoes phase change and decomposition of its constituencies with release of thermal energy. In this presentation the thermal decomposition properties of octol were investigated via DSC/TG method and Xray diffraction at various heating conditions. The thermal reactivity of heated octol was compared to other TNT based melt cast compositions, such as Composition B and cyclotol. 

C71.00353: Electrical and optical properties of tetragonal polymeric C60 under high pressure Zhongyan Wu, Lin Wang, Alexander Soldatov, Jaeyong Kim C60 having unique icosahedral truncated structure is known to form polymer or dimer between fullerene cages under high pressure and temperature. In this work the electrical and optical properties of 2dimensional tetragonal polymeric C60 were studied under high uniaxial pressure, p, to investigate the phase transformation. 

C71.00354: Structural behavior of silicate liquids and glasses under extreme conditions by using synchrotron Xray diffraction and Raman spectroscopy Young Jay Ryu, Tony Yu, Fiona Bonnet, Vitali Prakapenka, Sergey Tkachev, Heather Watson, Mark L Rivers, Yanbin Wang The behavior of silicate melts under highpressure and hightemperature conditions is of primary interest in the field of geophysical, chemical, material science, and technological glass process industry, both for their fundamental properties and for their significant roles in thermal transport and chemical differentiation within Earth and other terrestrial planetary interiors. Recently, considerable progress has been achieved in understanding the structural differentiation of liquid and glass silicates by both theoretical predictions and various spectroscopic experiments, yet still many issues are puzzling and several challenges must be overcome to expand our understanding of silicate liquids and glasses. Here, we report spectroscopic properties of enstatite (MgSiO3), wollastonite (CaSiO3), diopside (CaMgSi2O6) and silica (SiO2). The local atomic structure of various silicates has been studied using synchrotron angledispersive Xray diffraction combined with a multichannel collimator. Atomic pair distribution functions (PDFs) were obtained from the Xray data. Also, we have obtained the local vibrational modes by using Raman spectroscopy, providing additional structural information that cannot be obtained by Xray diffraction. 

C71.00355: Automated iterative forward analysis for pressure determination in dynamic compression experiments Connor Krill, Suzanne J Ali, June Wicks, Raymond Smith High powered laser compression experiments can provide insights into material behavior at solar and planetary cores  some of the most extreme conditions in the Universe. To fully understand material response at such extreme conditions, the pressure within the sample must be accurately determined. However, pressure cannot be measured directly. Experiments must measure the velocity of a sample and use knowledge of the equation of state to extract a pressure history. With new driver developments laser shot rate is increasing, going from once a day at NIF, to every few minutes at the Stanford Materials in Extreme Conditions (MEC) endstation and the nearterm subHz operation at the European Xray Field Electron Laser (XFEL) facility in Hamburg. This increase creates a need for an automated process to convert experimentally measured velocities into pressure histories. The work reported here implements an automated iterative forward analysis using the HYADES hydrocode that can scale with the growth of modern laser facilities to accurately retrieve pressure histories from a broad range of experimental conditions. We discuss this work in the context of ramp compression of various materials on the OMEGA laser facility. 

C71.00356: Liner Material Dependence on Penetration Ability of Metal Jet generated from MiniShaped Charge Devices against Iron Target Fumikazu Saito New experimental data for the mass and density gradients of Cu and Zn metal jet using the original massestimation method are reported. The metal jets were generated by using shaped charges, which consist of conical Cu / Zn liners and PBX explosive charge. To compare the penetration ability of these two metal jets, Fe targetblocks were used as the target. At 3 CD (3 times charge diameter; ca. 100 mm from the shaped charge device), the breakup of Cu jet was observed, and the Cu metal segment at the jet tip was generated. On the other hand, the breakup of the Zn jet was not observed at 3 CD. The tip of the Zn jet exhibited a cometlike tail, which is unique compared to the morphology of the Cu leading jet. This result shows that the Zn jet tip reaches a state of liquid, and/or becomes a fine particle at the initial formation process. Against expectations, the penetration depth of the Zn jet against the Fe target placed at 5CD from the shaped charge device was higher than that of the Cu jet having a relatively large initial density. This result suggests that the penetration depth is more affected by the total mass of the metal jet and that the liner geometry to generate the jet mass effectively is differ depending on the material properties such as density and melting point. 

C71.00357: Sizedependent toughness and strength in defective brittle nanowires Md Hossain Vacancy defects are ubiquitous in growing materials at the nanoscale. Yet their role in lowdimensional materials such as nanowires remains less understood. Here we report the observation of two mechanisms: elastic softening and stress localization that govern effective mechanical behavior of diamond and silicon carbide nanowires. They control different mechanical aspects of the nanowire at finite deformation. Elastic softening controls the effective mechanical properties such as stiffness in the linear regime of mechanical deformation, whereas stresslocalization affects the effective toughness and strength of the nanowire. As a result, the condition for crack nucleation and the direction of crack growth are directly controlled by the stresslocalization mediated by the higherorder elastic behavior of the lattice. With the increasing size of the defective regime, the nanowire shows softer effective elastic behavior that arises from the lowcoordinated atoms forming the basis for the softening state of the defective regime. Results show that defectsize dependent effective stiffness is controlled by softening at the defective and surface regimes, whereas defectsize dependent toughness and strength are controlled by stiffening of the material by secondorder elastic modulus. 

C71.00358: Different Types of Shear Stress Release in Metastable Olivine Maurizio Mattesini, Carolina LópezSánchez, Elisa Buforn Peiró, Agustín Udías Vallina A key element to understand the mechanism of shallowintermediate and very deep earthquakesis here provided by an accurate model description of the stressstrain curves of the subducting material, i.e. the metastable Olivine. Specifically, atomistic modeling was carried out throughab initiotechniques for the Mg_{2}SiO_{4}forsterite endmember at different pressure ranges. The achieved stressstrain relationships were finally compared to the Moment Rate SourceTime Functions (MRSTFs) and Fracture Energies values. We found that deep events have a common rupture pattern that differs substantially from that of shallowintermediate earthquakes. This finding is in line with the different behavior observed in the stressstrain curves as a function of depth. 

C71.00359: XRay Absorption Spectroscopy Fingerprints for bcc and hcp Iron at Earth’s Core Conditions Maurizio Mattesini, Anatoly Belonoshko The shapes of Fe Kedge of Xray absorption spectra (XAS) were theoretically computed at Core conditions by using a number of molecular dynamics snapshots from a previously equilibrated iron system at 360 GPa and 7000 K. Reference fingerprints for the different iron polymorphs, namely Febcc and Fehcp, were thus obtained within the multiscattering method and therefore proposed as specific spectroscopic fingerprints. It is shown that is possible to unfold the longstanding controversy about the structural complexity of iron at the Earth’s inner core conditions. Specifically, high pressure studies from static laser heated diamond anvil cell and dynamic compression can take advantage of the proposed spectroscopic fingerprints. 

C71.00360: Phase diagram of solid hydrogen Sam Azadi We present new results for the phase diagram of lowtemperature highpressure solid hydrogen, which are obtained using independentparticle and manybody wave functionbased approaches. To discover the nature of phase III, density functional theory calculations within the metageneralized gradient approximation by means of the strongly constrained and appropriately normed (SCAN) semilocal density functional are employed to investigate eleven molecular structures within wide pressure ranges of 100500 GPa. The SCANDFT predicts two structures of C2/c and P6_{1}22 as the best candidates for phase III. We employ the diffusion Monte Carlo (DMC) method to verify the stability of competitive phases which requires an accurate description of exchange interaction. Our DMC results indicate that the optimised percentage of exactexchange in manybody wave function equals to 40%. We name the corresponding exchange and correlation functional as PBE_{1}. The PBE_{1}predicted phase diagram shows that the phase III of highpressure solid hydrogen is polymorphic [1]. 

C71.00361: Coarsegrain simulation study of the shearband deformation mechanism in molecular crystals Sergei Izvekov, Patrick G. Lafond, John K. Brennan, James P. Larentzos Computationally inexpensive particlebased coarsegrained (CG) models are crucial for simulations of mesoscopically slow cooperative phenomena such as plastic deformations in solids. Molecular crystals possessing complex symmetry present an enormous practical challenge for coarsegraining at molecularly resolved scales, where the molecule is mapped into a CG particle and beyond. In this paper, we present the successful bottomup coarsegraining of a molecular energetic crystal, cyclotrimethylene trinitramine in the alpha phase (αRDX), using the forcematching based multiscale coarsegraining (a.k.a. MSCG/FM) approach.^{1} The new MSCG/FM model offers a potentially powerful freeenergy tool to analyze the lattice instabilities that lead to plastic response. A specific application of this model involves a study of the molecularlevel mechanisms of shear microband formation, which is observed in the atomistic simulations of αRDX under both static and shockwave uniaxial compressions. These were hypothesized to contribute to plasticity, and potential shock initiation in RDXbased explosives. 

C71.00362: Atomistic Predictions for Reaction Mechanisms, Kinetics, and Detonation Properties of the Insensitive Explosive LLM105 Alejandro H Strachan, Brenden Hamilton, Brad Steele, Matthew P Kroonblawd, IFeng W Kuo Understanding the mechanical and chemical characteristics of insensitive high explosives (IHEs) is key for the design of new insensitive materials with improved response. We explore high temperature reaction kinetics and identify reaction mechanisms for the IHE LLM105 through allatom molecular dynamics performed at two levels of quantum chemical theory and with classical reactive potentials. Short timescale DFTMD simulations are used to crossvalidate density functional tightbinding (DFTB) predictions, which in turn are compared against multiple ReaxFF parametrizations. Highthroughput DFTB simulations are coupled with the Hugoniostat technique to simulate shock loading and to characterize the Hugoniot curves for both unreacted LLM105 and its products. DFTB predictions for the CJ state and detonation properties are in good agreement with ReaxFFLG. Effects of pressure on reaction products and pathways are identified and isothermalisobaric simulations are used to study reactions at CJ conditions. Prepared by LLNL under Contract DEAC5207NA27344. Approved for unlimited release, LLNLABS793765. 

C71.00363: Development of lowadiabat drives for RayleighTaylor strength experiments Tom Lockard, Matthew P Hill, Andrew Krygier, Alex Zylstra, Peter Graham, Philip Powell, Damian C Swift, Shon T. Prisbrey, HyeSook Park, James M McNaney We have used the expansion of a shocked reservoir assembly across a gap to induce ramp loading, and hence infer strength from the growth of ripples at an interface. For multimegabar loading, the reservoir comprises a sandwich of several materials, and the resulting load history has a large amount of structure, including shocks. This structure leads to a degree of shock heating, and some uncertainty in the heating that actually occurs. We report on progress in studies to improve the reservoir drive by reducing the shock heating, including the performance of the models used for the components of the experiment in hydrodynamic simulations. 

C71.00364: LASER SCIENCE


C71.00365: Electron cyclotron emission with a helical wavefront in millimeterwave regime from an electron accelerated by a circularly polarized wave Yuki Goto, Shin Kubo, Toru Ii Tsujimura In this study, we calculated an Electron Cyclotron Emission (ECE) with a helical wavefront in the millimeterwave regime from an electron accelerated by a Circularly Polarized (CP) wave. Recently, it has been shown that radiation from a charged particle with spiral motion has a helical wavefront. Since an electron cyclotron motion is also a type of spiral motion, the ECE should also have a helical wavefront. In particular, we attempt to generate the high power coherent ECE with a helical wavefront from a multielectron system. Because the radiation with helical wavefront from a single electron is low power, the superposition of the electric field is necessary to detect the radiation. For this reason, the CP wave plays an important role to control the electron’ rotation motion. We have confirmed in the calculation that the rotation phase of the electrons is controlled by an externally applied CP electric field. It was also confirmed by calculation where the radiation from such the electron has a helical wavefront. We will show the details of the calculation results at the meeting. 

C71.00366: Evolution from Periodic Oscillation to Chaos in Qswitched Vortex Lasers of a Unit Topological Charge YuanYao Lin, ChaoYi Wu Recently direct vortex lasing from azimuthal symmetry breaking resonator were demonstrated both in continuous wave [1] and in Qswitched [2] operations. Regarding to the investigation of laser dynamics we rebuild the Qswitched vortex laser system following the same configuration reported in REF [2]. Produced Qswitched laser emits annular intensity pattern and its positive unit topological charage is quantified by spiral phase pattern sensed using a interferometer. Clear transition from periodic oscillation of every 2 pulses, 4 pulses and 6 pulses to completely disorders in pulse sequences can be identified in delay maps using the pulsetopulse duration as an observable. This spatialtemporal dynamic can be explained by TangStatzDeMars model that describes the coherent coupling and nonlinear interactions of the offaxis multiple pass resonance modes. Moreover pumping a KTP crystal by this Qswitched vortex laser at the wavelength of 1064 nm, second harmonic wave at 532 nm exhibits unconventional intensity distribution other than a vortex with doubling topological charges because of the interactions among the resonating offaxis modes in fundamental wave. 

C71.00367: Discrete evolution on temporal separation and phase difference for bound solitons in an Yb modelocked fiber laser Cecília Campos, Lucas B. A. Mélo, Lúcio H. Acioli, Marcio H. G. de Miranda Multiple pulse regime is a common feature in passively modelocked fiber lasers (MLFL). They could either be equally spaced, randomly distributed or arranged in a state of close interacting pulses. The later is often called bound solitons and presents strong modulation in the optical spectrum, which contains information about average relative phase, Δφ, and temporal separation between the pulses, τ. In this work, we study how increments in the total intracavity energy act on τ and Δφ for an Yb MLFL. For this, we continuously monitored the optical spectrum and the autocorrelation as the pump power was increased. We observed a discrete nature of τ, which is in agreement with previous works that observed its quantization for Erdoped fiber lasers [1] and predicted the quantization of binding energy between bound solitons [2]. Our work provides a systematic experimental study capable of capturing the jumps in τ, besides reporting a discrete behavior that is also present in Δφ. 

C71.00368: ATOMIC, MOLECULAR, AND OPTICAL PHYSICS


C71.00369: Using Light to Simulate the Quantum Mechanics of the Simple Pendulum Enrique Galvez, Jake Freedman, Yingsi Qin, Fabio J Auccapuclla, Kristina Wittler We present experiments with a type of nondiffracting optical beams that satisfy a form the 2dimensional Helmholtz equation that is identical to the Schrodinger equation for the simple pendulum. This form is known as the Mathieu equation. As a result the optical beams are in spatial modes that are related to the quantum solutions of the pendulum. The light intensity in the far field is propostional to the probability of the pendulum bob as a function of the angular position. Depending on the parameters of the problem we can select either states that describe the pendulum swinging or rotating. This system also allows us to investigate an array of interesting quantum phenomena: stationary states with nonclassical analogs, wavepacket revivals and even cat states. 

C71.00370: Effects of Spinorbitcouplinginduced Resonance in Ultracold Bosonic Systems yuncheng xiong, Lan Yin We calculate renormalized twobody interactions using Tmatrix method, which is the sum of all orders of ladder diagrams in the bare basis. Apart from corrections to three types of diagonal interactions, there emerge many offdiagonal ones. We interpret the divergence of Tmatrix as SOCinduced resonance, with the aid of which, the contrast of density modulation in stripe phase in Rb87 can be enhanced by ten times of its original value and wavelength enlarged by two times so that the stripe phase may be observed directly with conventional absorption image technique. Besides SOCinduced resonance, we also recalculate the critical value for StripePlane wave transiton which is shifted by a small value. Finally, we find the correction to the density profile when Raman coupling Ω>4E_{r}. 

C71.00371: Phonon Stability and Sound Velocity of Bose Mixture Droplet Qi Gu, Lan Yin When the meanfield energy is as small as the quantum fluctuation, the selfenergies under Bogoliubov approximation do not necessarily include all the contributions of the same order. For quantum droplets of a Bose mixture, the lower Bogoliubov mode is unstable at small momentum. Considering all the same order selfenergies, the excitation spectrum is qualitatively different from the Bogoliubov mode. We develop Beliaev's method to calculate the elementary excitation and phonon velocity accurate to the order of gas parameter (na^{3})^{½} in the homogeneous droplet. We discuss quasiparticles' Beliaev damping and find that density phonons are almost undamped . The sound velocity is found to be positive, which determines the nonzero superfluid critical velocity of droplet. In experiments, our results can be tested by measuring sound speed, superfluid critical velocity or collective mode. 

C71.00372: Quenchproduced solitons in a boxtrapped BoseEinstein condensate Eli Halperin, Michelle Wynne C Sze, John Corson, John L Bohn We describe a protocol to prepare solitons in a quasi1d boxtrapped BoseEinstein condensate using only a quench of the isotropic swave scattering length. A quench to exactly four times the initial scattering length creates one soliton at each boundary of the box, which then propagate in a uniform background density and collide with one another. No nonsolotonic excitations are created during the quench. We investigate the robustness of this procedure to the scattering length ramp rate and a mismatch of the final scattering length. 

C71.00373: Manipulation of cold chiral molecules using electronic and rotational spectroscopy Alicia HernandezCastillo, Johannes Bischoff, Ju Hyeon Lee, Marco De Pas, Henrik Haak, Gerard Meijer, Sandra I Eibenberger The two nonsuperimposable mirror images of a chiral molecule are referred to as enantiomers; that is, structures that cannot be transformed into each other by pure translation or rotation. Many molecules of biological interest have a stereogenic center that determines their functionality. However, most physical properties of enantiomers are identical, thus, chiral analysis remains a challenge, and there is a need for fast and reliable methods that can differentiate and/or separate enantiomers. Recently, the enantiomerspecific state transfer method^{1} was developed. This method provides the means to populate or depopulate a rotational state of an enantiomer. We have designed, built, and characterized a compact spectrometer capable of performing chirpedpulse Fourier transform microwave and electronic spectroscopy. By combining optical methods with microwave spectroscopy, we seek to maximize the statespecific enantiomeric enrichment. We also implement more sensitive detection schemes such that small population changes can be detected. Recent experimental results and details on the new spectrometer will be discussed. 

C71.00374: Photoassociation of Fermionic ^{87}Sr via the ^{1}S_{0}  ^{1}P_{1} Transition Joshua Hill, Thomas Charles Killian The fermionic isotope of strontium, ^{87}Sr, is of interest for the development of optical frequency standards and the study of quantum manybody phenomena. In many of these experiments, ^{87}Sr is confined in an optical lattice. Detecting the presence of doubly occupied lattice sites is a valuable tool for studies of atomic gases in optical lattices, and this is typically done with photoassociation, in which two goundstate atoms in a scattering state are photoexcited to a molecular state. No resonance frequencies have been reported for transitions to molecular states of any excited electronic potential for ^{87}Sr. Here we present results for photoassociation of ^{87}Sr atoms via the ^{1}S_{0}  ^{1}P_{1} transition at 461nm (Γ=(2π*30.5)s−1), and measurements of optical lengths for select photoassociation spectra. 

C71.00375: Cold polar molecules in superfluid helium nanodroplets: Electrostatic deflection of imidazole, its complexes and fragments Benjamin Kamerin, John W Niman, Vitaly V Kresin Helium nanodroplet isolation is a unique method for investigating molecules and molecular structures captured in an inert, superfluid matrix. In particular, it is a highly productive tool for the study of very cold polar molecules and their assemblies. We recently demonstrated that beams of nanodroplets doped with polar molecules can be interrogated by electrostatic deflection, leading to remarkably large deflections on the order of millimeters. Here we apply this method to the imidazole molecule, which is a fivemembered polar ring which plays an important role in biological processes. We are able to differentiate polar complexes of imidazole by their dipole moments, and identify their fragmentation pathways. 

C71.00376: Structures with local minima at low energies in abovethreshold ionization electron spectra Dmitry A. Telnov, ShihI Chu


C71.00377: A relativistic singleparticle potential for photoexcited electron orbitals of openshell atoms James Boyle A singleparticle potential for the calculation of relativistic photoexcited electron orbitals is introduced. Based upon the earlier work of Qian et al. (Phys. Rev. A 33, 1751 (1986)) and Boyle (Phys. Rev. A 48, 2860 (1993)) for nonrelativistic electron orbitals, this relativistic potential is defined to include exactly all of the firstorder electron correlations that appear in the diagrammatic perturbation series of the dipole polarizability and that contain potential corrections in the intermediate state. Analytic relationships associated with initial state jjcouplings are also considered. For example, among other things, the ability to rewrite the defined relativistic potential for a final state as an average term plus a correction to the defined average is investigated and presented. 

C71.00378: The Link between Artificial Neural Networks and Propagation in Random Media Giulia Marcucci, Davide Pierangeli, Claudio Conti Random media (RM) with tailored optical properties are attractive for their many applications. Transmission channels (TCs) in RM can be effectively controlled, and their rich behavior is due to the multitude of interacting optical modes. We demonstrate that TCs in RM act as an untrained artificial neural network (ANN), as deep as the amount of perturbations. This lets us obtain a random optical machine (ROM), able to do computation by reservoir computing (RC). 

C71.00379: Infinite temperature adiabatic flows and quantum manybody scar states in a chaotic system Sho Sugiura, Pieter W Claeys, An Dymarsky, Anatoli S Polkovnikov Under any operation in manybody chaotic systems, quantum states usually experience dissipation. However, this dissipation can be drastically suppressed through the application of additional appropriate control fields, as is done in counterdiabatic driving. Here, we restrict control to fewbody operations and draw flows of the optimal path for quantum control in a nonintegrable Ising chain. We find that these flows are highly anisotropic; we can realize almost dissipationless driving in one direction while dissipation is hard to reduce in the perpendicular direction. This indicates that the choice of the path is crucial for quantum operations in manybody chaotic systems. Furthermore, states which are eigenstates of the counterdiabatic term are shown to exhibit small dissipation even without counterdiabatic fields, and are closely related to quantum manybody scar states and manybody dark states. 

C71.00380: AtomLight Interactions in Integrated Photonics: en Route to an Atomic Lab on a Photonic Chip Hadiseh Alaeian, Artur Skljraw, Robert Loew, Harald Kuebler, Tilman Pfau The integration of photonic structures with thermal atomic vapors on a chip provides efficient atomlight coupling on a miniaturized scale well beyond the diffraction limit hence, opening a new regime in the field of cavity quantum electrodynamics. In this talk, we present the results of our study on interactions of thermal Rb atoms with integrated SiN and Si Nanodevices. In the former case, the atoms are probed with a laser at the D_{2} transition, whereas in latter the atoms are further excited to the 4D states with an additional excitation at telecom wavelength. Our studies on Si structures benefit from stronger mode confinement due to the large reflective index as well as a larger dipole moment. Moreover, we demonstrate novel measurements on the effects of Si surface potentials on Rb 4D states. Promising results on ring resonators pave the way towards further investigations of highQ photonic crystal cavities in order to reach the strong coupling regime. 

C71.00381: An optical fiber simulator of three interacting atoms in one dimensional parabolic trap Miguel GarciaMarch, Nathan L Harshman, Thomas Fogarty, Heitor Da Silva, Thomas Busch, Maciej A Lewenstein, Albert Ferrando We introduce an optical fiber that simulates a system of three trapped ultracold and strongly interacting atoms in onedimension. To simulate the contact interactions among the atoms, we consider a sharp and narrow jump in the refractive index. To this end, we consider here three thin metallic slabs. To simulate the parabolic trap we assume that the fiber has a graded refractive index profile. While the wavenature of single quantum particles leads wellknown analogies with classical optics, for interacting manyparticle systems such analogs are not straightforward. We discuss: i) how by spatially modulating the incident field, one can select the atomic statistics, i.e., emulate a system of three bosons, fermions or two bosons or fermions plus a distinguishable particle; ii) how this system can produce classical nonseparability resembling that found in the analogous atomic system. 

C71.00382: Surface plasmonpolariton waves propagation and excitation along the direction of periodicity of the onedimensional photonic crystal Muhammad Faryad, Muhammad Kamran, Mehran Rasheed The surface plasmonpolariton (SPP) waves guided by onedimensional photonic crystals (1DPCs) are usually excited at the interface perpendicular to the direction of periodicity. In this work, we will present the formulation and the numerical results delineating the excitation of the SPP waves on the interface perpendicular to the direction of periodicity. Both the eigenvalue problem of finding and solving the dispersion equation and the problem of the excitation of the SPP waves will be discussed. The eigenvalue problem is solved using the rigorous coupledwave approach. The results indicate the presence of the plasmonic bandgap that can help in designing the plasmonic optical filters. 

C71.00383: Anomalous magnetic moment of electron for an adiabatically changed Finslerian manifold. Armando Meza Gaxiola, Anton Lipovka In present work, we resolve the unified equation of motion for a quantum system on the adiabatically changed Finsler manifold, suggested by Lipovka (2017), for the particular case of the hydrogen atom. The radial part for the equation of motion is obtained to model a hydrogen atom, where the electron and the nucleus rotate around a center of mass. By using this expression, the total energy of the system under consideration (charged particles and EM field) is obtained. 

C71.00384: Optical spectroscopy of TaH: Six lowlying electronic states and their agreement with computational studies Thomas Varberg, Samuel P Gleason, Dalir H. P. Kellett, Paul P. Reischmann We have recorded electronic spectra of tantalum hydride (TaH) over the region 605–665 nm. The spectra were recorded by laser excitation spectroscopy at Dopplerlimited resolution using a continuouswave ring dye laser. We have assigned and fitted a total of 12 different bands, which originate from one of three lowlying electronic states. Calculations by Mark Gordon’s group and previous experimental work in our group confirm that the Ω = 2 ground state is largely derived from a σ^{2}δπ, ^{3}Φ_{2} state. An Ω = 0^{+} state, largely a mixture of ^{3}Σ^{–} and ^{3}Π, lies only 76 cm^{–1} above the Ω" = 2 ground state. By recording dispersed fluorescence, we found and characterized a total of six lowlying states of the molecule. The electronic states have been fitted by leastsquares using a Hund’s case (c) Hamiltonian. We report term energies, vibrational frequencies, rotational and centrifugal distortion constants, and bond lengths for these states, which were found to be in good agreement with the computational results. 

C71.00385: The Physics of Critical Heat Flux Studies for Innovative ATF Cladding Surfaces Kaya Mondry Overall Objective 

C71.00386: Floquet approach to the study of the dynamical Lamb effect Mirko Amico, Roman Kezerashvili The dynamics of N qubits coupled to a harmonic oscillator with timeperiodic coupling is investigated in the framework of Floquet theory. This system can be used to model nonadiabatic phenomena that require a periodic modulation of the parameters of the system. An example is the dynamical Lamb effect, the simultaneous excitation of the qubits and the harmonic oscillator out of the ground state due to the nonadiabatic change in boundary condition of the system. The timedependent Schroedinger equation describing the system’s dynamics is solved within the Floquet formalism and two other equivalent methods that rely on a perturbative approach in the time and Laplacedomain. Because of the periodicity of the problem analyzed, the Floquet formalism provides a framework where analytical and numerical results are closest to each other. Nonetheless, the time or Laplacedomain perturbative approaches can be used in the presence of simple or complicated, respectively, aperiodic timedependent terms in the Hamiltonian. 

C71.00387: Symmetric Rotating Wave Approximation for the Generalized TwoMode TwoPhoton System Coupled with a Bosonic Field David Wu We study the analytically approximated eigenenergies of the twomode twophoton quantum Rabi model coupled with a Bosonic field. By equipping the previously established generalized symmetric rotating wave approximation (GSRWA) method used on singlemode spinboson systems with a unitary squeezing operator and applying it onto the twomode twophoton system, we obtain a more generalized and simplified closedform expression for eigenenergies of the system compared to other expressions derived using the functional Bethe ansatz method. We further investigate the effectiveness of the squeezing operator by examining the eigenenergies of the generalized resonant and nonresonant case for the twolevel twophoton system. The accuracy of the updated GSRWA method in the ultra and deepstrong coupling regimes reveals interesting symmetries within the mathematical structure of the twolevel twophoton systems. 

C71.00388: Topological Control of Extreme Nonlinear Waves Giulia Marcucci, Davide Pierangeli, Aharon J. Agranat, RayKuang Lee, Eugenio DelRe, Claudio Conti Controlling nonlinear optical processes is a significant challenge in photonics. Shock waves, rogue waves and solitons are widespread, from optics to hydrodynamics. Intense research is dedicated to advanced techniques for tailoring extreme waves and finding the conditions to induce transitions between different waves. 

C71.00389: Theory of HighEnergy Electron Thermionic Emission from Graphene liemao cao, yueyi chen, Lay Kee Ang, Yee Sin Ang Graphene thermionic electron emission across high barrier involves energetic electrons residing far away from the Dirac point. In this work, we construct a fullband model beyond the simple Dirac cone approximation for the thermionic injection of highenergy electrons in graphene [1]. We show that the thermionic emission model based on the Dirac cone approximation is valid only in the graphene/semiconductor Schottky interface operating near room temperature but breaks down in the cases involving highenergy electrons. We further reveal a critical potential barrier height beyond which the Dirac cone approximation crosses over from underestimation to overestimation. In the hightemperature thermionic emission regime, the Dirac cone approximation severely overestimates the electrical and heat current densities by more than 50% compared to the more accurate fullband model. Our findings reveal the fallacy of Dirac cone approximation in the thermionic injection of highenergy electrons in graphene. The fullband model developed here can be readily generalized to other 2D materials and shall provide an improved theoretical avenue for the accurate analysis, modeling and design of graphenebased thermionic energy devices. 

C71.00390: Generation of optical vortices from a spatial light modulator, vortex phase plate, and mode converter TingHua Lu, TengDe Huang First introduced in 1992 by Prof. Allen et al., light with orbital angular momentum (OAM), also called the Laguerre–Gaussian mode, possesses an OAM of per photon. Its twisted phase wavefront is a manifestation of the azimuthal phase term in its wavefunction, while the phase singularities along the beam axis are defined as the optical vortices. The twisted light which possesses OAM can be generated by laser cavities, spiral phase plate, metalens, and spatial light modulator (SLM). In this work, we utilize a vortex phase plate, mode converter, and spatial light modulator to generate highorder vector vortex beams. The mode converter is used to transform the vortex beam with circular symmetry into rectangular symmetry and form the vortex array. This is a convenient and powerful method to produce and control the optical vortex array of the vector superposed optical field, which is composed of different orders of crossed HermiteGaussian bases with opposite helicity of circular polarization. The SLM provides an extra degree of freedom to increase and control the order of the bases in the vector superposed optical field, which can induce optical vortices of different sizes and quantities. 

C71.00391: Multipole Excitation of C_{60} Molecules in a SemiClassical Approach Krishna Lamichhane


C71.00392: Ab Initio Potentials for LowEnergy Positronium Scattering Jesse Kinder This poster presents ab initio potentials for positroniumatom and positroniummolecule interactions. Two methods are used to calculate the potential energy: selfconsistent solution of the HartreeFock equations and solution of the KohnSham equations at the level of the local density approximation. The total energy is computed for a wide range of positroniummolecule separations, molecular orientations, and basis sets. Comparing the two methods illustrates the importance of both electronelectron and electronpositron correlations in obtaining realistic potentials. 

C71.00393: New Atomic Model from the spectra of Hydrogen, Helium, Beryllium, Boron, Carbon, and Deuterium and their ions Janeen Hunt A cohesive unifying theory of the atom does not currently exist in Quantum Physics. In this research, the atomic spectra are allowed to determine the model for the atom based upon the finding of patterns of the BalmerRydberg formula in the first 20 ions and neutral atoms of the periodic table. From this data, the model postulates a standing wave of varying energy antinodes originating from the particles in the nucleus of each atom which is able to predict the ionization energies of these atoms. The transitions of the electrons in atoms are defined by the energies of each antinode represented by the difference in energy between each spectral line. The spectral patterns for H, HeI, HeII, LiI, LiII, LiIII, BeI, BeII, BeIII, BeIV, BI, BII, BIII, BIV, BV, CI, CII, CIII, CIV, and Deuterium are charted and the ionization energies are calculated from the data including general inferences this model predicts about the unification of atomic forces, electron transitions, heat, and electromagnetism. This model predicts that the nucleus of every atom is held together by energy in the form of a standing wave originating from the nucleus and surrounding it. This is the Sollism Theory of the atom. 

C71.00394: WITHDRAWN ABSTRACT


C71.00395: Casimir Juggling Connor Hafen, Daniel Sheehan Casimir forces can dominate system behavior at the nanoscale; 

C71.00396: Survey of Molecular Rotational Transitions for MillimeterWave Frequency Metrology. Mark Yeo, Antoine Rolland, Tomohiro Tetsumoto Userdefined, spectrally pure and tunable millimeterwave oscillators, using emerging photonic technologies, enables the probing of pure rotational molecular transitions (from 30 GHz to 1 THz). This work promises to open new applications in frequency metrology, precision molecular spectroscopy, and trace gas sensing. Here we report a theoretical survey of a wide range of molecular candidates to compare their suitability for use in a rotational based clock. We will report calculations that lead to theoretical estimations of clock factors of interest such as line positions and strengths, and sensitivity to environmental perturbations. This work will provide an understanding of the utility of ultraprecise measurements of the rotational spectrum in blooming applications such as radioastronomy and remote sensing, noninvasive sensing, wireless communications, and for THz frequency metrology. 

C71.00397: WITHDRAWN ABSTRACT


C71.00398: WITHDRAWN ABSTRACT


C71.00399: Design of a viable radiationbalanced fiber laser or amplifier Arash Mafi, Mostafa Peysokhan, Esmaeil Mobini


C71.00400: Uncovering the Role of Excited States of Dication in Controlling the Dissociative Double Ionization of Ethane Gihan Basnayake, Duke Debrah, Wen Li With the aid of newly developed coincidence detection imaging system, we demonstrate that the branching ratios of dissociative double ionization channels of ethane can be controlled by varying the ellipticity of the intense ultrashort laser pulses. The CH_{3}^{+} formation channel and H^{+} formation channel show a significant yield changes, producing the highest and lowest at ellipticity of 0.59 respectively. With the help of theoretical calculations, we attribute such a control to both angle dependent ionization and intensity dependent ionization to excited dication states. 

C71.00401: High bandwidth, bidirectional microwave to telecom conversion using an electrooptic transducer operating at millikelvin temperatures William Hease, Alfredo Rueda, Rishabh Sahu, Johannes Fink


C71.00402: Towards cavity quantum circuit electromechanics with millimitersized silicon nitride membranes Sarwan Peiter, ADRIAN SANZ MORA, Gary Steele Due to their extremely high mechanical quality factors, silicon nitride membranes are commonplace in optomechanical experiments conducted with light fields. However, to strongly couple optical radiation to the vibratory motion of such membranes down in the quantum regime is still a soughtafter target in these experiments. 

C71.00403: Acoustic modes of superfluid helium in a cross geometry Vaisakh Vadakkumbatt, Thomas Clark, Swati Singh, John Davis Superfluid helium is a lowloss optomechanical element, and an acoustic quality factor value up to 10^{8 }has been realized experimentally in a macroscopic quantum system using a cylindrical microwave cavity [1]. It has been predicted that three orders higher quality factor may be attained with improvements to the experimental system. With these parameters, superfluid helium is a potential candidate for detecting continuous gravitational waves [2]. Here, we study the acoustic modes of superfluid helium inside a cross geometry using a reentrant microwave cavity that provides improved detection of the acoustic modes. The cross shaped geometry is also predicted to be more sensitive than a cylinder for detection of gravitational waves. 

C71.00404: Coherent coupling completes an unambiguous optomechanical classification framework Xiang Li, Mikhail Korobko, Yiqiu Ma, Roman Schnabel, Yanbei Chen Cavity optomechanics studies the dynamics of systems in which optical and mechanical degrees of freedom are coupled, e.g., optical resonators with movable/deformable boundaries and/or shapes. A system's behavior depends crucially on the nature of optomechanical coupling. In addition to the previously wellknown dispersive (when real parts of optical eigenfrequencies depend on mechanical displacement) and dissipative coupling (when imaginary parts of optical eigenfrequencies depend on mechanical displacement), we identify coherent coupling as a new type of coupling (when neither depend on mechanical displacement) and show that the three together fit into a general, unambiguous classification framework. We discuss in detail a ring cavity with a movable mirror inside, a system that has pure coherent coupling without any dispersive or dissipative coupling. 

C71.00405: Twotone optomechanical instability and its fundamental implications for backactionevading measurements Itay Shomroni, Amir Youssefi, Nick Sauerwein, Liu Qiu, Paul Seidler, Daniel Malz, Andreas Nunnenkamp, Tobias J. Kippenberg We report a new type of optomechanical instability that arises in twotone backactionevading (BAE) measurements of mechanical motion, a protocol designed to overcome the standard quantum limit. We demonstrate the effect both in the optical and microwave domains using different optomechanical systems, and find excellent agreement with theory. In contrast to the wellknown parametric instability that occurs in singletone, bluedetuned pumping, and results from a twomode squeezing interaction between the optical and mechanical modes, the twotone instability results from singlemode squeezing of the mechanical mode due to small detuning errors in the two pump frequencies. The instability can occur even with balanced intracavity fields and for both signs of detuning errors. The required tuning accuracy increases with pump power, putting an intrinsic limit on the sensitivity of BAE measurements and on other twotone schemes. 

C71.00406: Ultraviolet resonator integrated in a hollowcore fiber for Xenon plasma lasing Jeremy Flannery, Sema Kuru, Supratik Sarkar, Vinodh Raj Rajagopal Muthu, Michal Bajcsy We integrate a cavity in a largediameter hollowcore optical fiber based on inhibited coupling as a step towards realization of a fiberintegrated gas laser in the ultraviolet (UV) region. This is accomplished by attaching highly reflective photonic crystal (PC) membranes onto the ends of a fiber segment to form a FabryPerot cavity. The PC membranes are fabricated using ebeam lithography and reactive ion etching, which are then mounted on the fiber face using a micromanipulator stage. The presence of the PC holes allow for injection loading of atomic species into the fibercavity. Specifically, Xenon gas can be introduced through the perforated membrane into the hollowcore of the fiber to act as a gain medium for UV lasing when exposed to RF discharge. 

C71.00407: Numerical Modeling of Optomechanical Sensors for Dark Matter Detection Russell Stump, Jack Manley, Swati Singh Ultralight scalar dark matter can be represented as an atomic strain that can drive the acoustic breathing modes of an elastic body. We propose various laboratoryscale mechanical resonators for measuring the acoustic excitations at frequencies ranging from kilohertz (kHz) to Gigahertz (GHz)[1]. These devices include bulk acoustic wave resonators, phononic crystals, superfluid helium detectors and suspended sapphire micropillars. We use numerical modeling techniques to characterize each device’s performance as a dark matter detector. These techniques can be applied to an arbitrary mechanical resonator to measure its viability as a sensor for these signals. 

C71.00408: Observation of dynamical quantum phase transitions in spinor condensates with no correspondence in groundstate phase diagram Haoxiang Yang, Tian Tian, LiYuan Qiu, Haiyu Liang, Yanbin Yang, Yong Xu, Luming Duan Dynamical quantum phase transitions are closely related to equilibrium quantum phase transitions for ground states. Here, we report an experimental observation of a dynamical quantum phase transition in a spinor condensate beyond this conventional wisdom. We observe that the quench dynamics exhibits a nonanalytical change with respect to a control parameter in the absence of a corresponding phase transition for the ground state there. We make a connection between this singular point and a phase transition point for the highest energy level in a subspace with zero spin magnetization of a Hamiltonian. We further show the existence of dynamical phase transitions for finite magnetization corresponding to the phase transition of the highest energy level in the subspace with the same magnetization. Our results open a door for studying dynamical phase transitions beyond the conventional groundstate phase diagram and using them as a tool to probe the phase transitions at higher energy eigenlevels of manybody Hamiltonians. 

C71.00409: Hydrodynamics of shock waves in ultracold nondegenerate dipolar gases. Reuben Wang, Andrew Sykes, John L Bohn The hydrodynamics of an ultracold, nondegenerate gas of harmonically trapped dipolar atoms is studied. We numerically simulate this system using direct simulation Monte Carlo methods in the regime where interactions are dominated by twobody collisions, as for instance can be achieved in ultracold gases of Dy or Er. We subject the gas to a shortpulse perturbation which is common in hydrodynamic studies of shock waves, emphasizing the anisotropies in hydrodynamic phenomena resulting from the anisotropic collision cross sections of the diploles. This work extends observations of anisotropic rethermalization of a cold, dipolar gas previously seen in [1,2]. Here, shock wave hydrodynamics is studied in the less explored lowtemperature regime, leading to a emergence of rich phenomena. This work was supported by the NSF. 

C71.00410: Selforganization and stroboscopic dynamics of a driven Rydberg gas Kai Klocke, Michael Buchhold Motivated by recent experiments observing signatures of selforganized criticality (SOC) in driven Rydberg ensembles, we develop a Langevin description to explore how SOC can emerge from the microscopic interactions in experimental Rydberg setups. We demonstrate that drift and diffusion of atoms arising from an inhomogeneous trapping potential capture the stroboscopic evolution observed in experiments. The trap dynamics induces a continuous reorganization of the atoms, which pins the central density to a critical point and gives rise to scale invariant excitation avalanches. We further discuss how additional external driving can be used to extend and manipulate the SOC avalanche dynamics. This offers a detailed perspective on how avalanche dynamics can be controlled in driven Rydberg gases. 

C71.00411: Photon blockade in the Tavis Cummings model Rahul Trivedi, Marina Radulaski, Kevin A Fischer, Shanhui Fan, Jelena Vuckovic We use the scattering matrix formalism to study single and twophoton transport through the Tavis Cummings model as a function of the number of emitters coupling to the cavity mode. It is shown that for a resonant Tavis Cummings system, photon blockade at the output of the cavity mode worsens with the number of emitters while for a detuned Tavis Cummings system, photon blockade at the output of the cavity mode improves with the number of emitters. By explicitly calculating the twophoton scattering properties of this system in the thermodynamic limit of an infinite number of emitters, we show that the light emitted from Tavis Cumming system under excitation by a coherent drive transitions from bunching to antibunching as the emitters are detuned from the cavity mode. Finally, we analyze the impact of inhomogeneous broadening in the emitter frequencies on both resonant and detuned photon blockade through the Tavis Cumming system. 

C71.00412: Pointcoupling Hamiltonian for frequencyindependent linear optical devices Rahul Trivedi, Kevin A Fischer, Sattwik Mishra, Jelena Vuckovic We present the pointcoupling Hamiltonian as a model for frequencyindependent linear optical devices acting on propagating optical modes described as a continua of harmonic oscillators. We formally integrate the Heisenberg equations of motion for this Hamiltonian, calculate its quantum scattering matrix, and show that an application of the quantum scattering matrix on an input state is equivalent to applying the inverse of classical scattering matrix on the annihilation operators de scribing the optical modes. We show how to construct the pointcoupling Hamiltonian corresponding to a general linear optical device described by a classical scattering matrix, and provide examples of Hamiltonians for some commonly used linear optical devices. Finally, in order to demonstrate the practical utility of the pointcoupling Hamiltonian, we use it to rigorously formulate a matrix productstate based simulation for timedelayed feedback systems wherein the feedback is provided by a linear optical device described by a scattering matrix as opposed to a hard boundary condition (e.g. a mirror with less than unity reflectivity). 

C71.00413: Efficient numerical integration of the adiabatic master equation Humberto MunozBauza, Daniel A Lidar The capability to simulate open quantum systems under the adiabatic condition is critical for verifying the behavior of quantum annealers. While adiabaticity is a useful condition for theoretical analysis, straightforward numerical implementations of the adiabatic master equation (AME) suffer from the need to integrate an adiabatic but highly oscillatory quantum state over a very long period of time. We show that the AME in the adiabatic frame can be split in a way that prevents large superoperator evaluations and is amenable to geometric integration methods for split timedepedent problems. 

C71.00414: A perturbative view from the master equation: Electromagnetically induced transparency revisited Xin Wang We show that by treating the weak probe field as a perturbation to the strong coupling 

C71.00415: Vacancies effect on the BEC critical temperature of an ideal Bose gas within an imperfect crystal Miguel A. Solis, Emilio I Guerrero After we have shown [1] that an ideal Bose gas in one, two or threedimensional crystal with one structural vacancy presents BoseEinstein condensation (BEC) at higher finite critical temperature than that when the crystal is perfect; here we report the BEC critical temperature as a function of the number of random vancancies. The particle energy spectrum is obtained using finite difference numerical method, which we use to calculate the critical temperature as the temperature at which the isobaric specific heat has its maximum [2]. When our finite system is taken to the thermodynamic limit, the critical temperature starts at the one vacancy value, it increases reaching a maximum when we have about 17 % of vacancies and then decays almost linearly to zero when the crystal has been removed. 

C71.00416: Quantum system chaos in a PTsymmetry breaking potential Carla Quispe Flores, Ines de Vega, Renan Cabrera, Lincoln Carr We studied the dynamics of N bosons confined in a triple well potential in phase space. The system is tackled by using the truncated Wigner approximation (TWA) and exact diagonalization of BoseHubbard model including a perturbative PTsymmetry breaking potential. We find a region in which the symmetry breaking develops smoothly with the control parameters enabling to break many symmetries of the Hamiltonian and reduce energy degeneracies. The model shows signatures of stationarity, chaos and mixing as a consequence of the interparticle interactions. Generation of entangled states and loss of purity is also observed and monitored by the Meyer’s measure of the impurity and the von Neumann entropy S. Finally, the system chaotic behavior is conveniently tracked within the phase space by the growth rate of the outoftime ordered correlator. 

C71.00417: Continuous protection of a quantum state from inhomogeneous dephasing Ran Finkelstein, Ohr Lahad, Omri Davidson, Eilon Poem, Ofer Firstenberg Roomtemperature atomic vapors are known for their simplicity and their potential scalingup in applications. In spite of these benefits, lasercooled atoms have evolved to be the prevalent systems for studying strong and coherent lightmatter interactions, as the latter are unhindered by Doppler broadening. 

C71.00418: Combined spontaneous symmetrybreaking and symmetryprotected topological order from cluster charge interaction Chen Peng, YuanYao He, RongQiang He, ZhongYi Lu The study of symmetryprotected topological states in presence of electron correlations has recently aroused great interest as rich and exotic phenomena can emerge. Here, we report a concrete example by employing largescale unbiased quantum Monte Carlo study of the KaneMele model with cluster charge interactions. The groundstate phase diagram for the model at half filling is established. Our simulation identifies the coexistence of a symmetryprotected topological order with a symmetrybreaking Kekule valence bond order and shows that the spontaneous symmetrybreaking is accompanied by an interactiondriven topological phase transition (TPT). This TPT features appearance of zeros of singleparticle Green's function and gap closing in spin channel rather than singleparticle excitation spectrum, and thus has no meanfield correspondence. 

C71.00419: Quantum Monte Carlo Simulations of the Attractive SU(3) Hubbard Model on a Honeycomb Lattice Yu Wang, Han Xu, Lei Wang We perform the projector quantum Monte Carlo simulation of the halffilled attractive SU(3) Hubbard model on a honeycomb 

C71.00420: Signatures of Majoranalike Quasiparticles in Fewbody Lattice Models Jared Bland, Birgit Kaufmann, Chris H Greene There is a strong interest in number conserving systems that exhibit Majorana fermions as quasiparticles. We utilize a numberconserving analog of the Kitaev wire model due to Iemini et al. in the smalllattice limit to examine signatures of topological properties in small systems. This interacting model exhibits several signatures of topological regime, such as identical entanglement spectra for the ground states in distinct parity sectors. Additionally, the Hamiltonian is akin to the BCS Hamiltonian, suggesting Bogoliubov rotations and approximations, allowing us to further examine this model in this regard. In this work, we demonstrate these signatures of different topological order in small lattice sizes to find evidence of isolated Majorana quasiparticles. 

C71.00421: Effect of Core Size on Vortex Interactions in Light Jasmine Andersen, Andrew A. Voitiv, Mark T. Lusk, Mark Siemens Optical vortices are characterized by a helical wavefront with integer winding, also referred to as 

C71.00422: Finite Orbital Angular Momentum Pairing in Atomic Fermi Gases with SpinOrbitalAngularMomentum Coupling Wang LiangLiang FuldeFerrellLarkinOvchinnikov states represent superconducting states with finite momentum Cooper pairs and have become one of most soughtafter exotic states of matter. The recent realization of a new type of spinorbit coupling in ultracold atomic gases, namely the spinorbitalangularmomentum coupling, provides a novel perspective to study FuldeFerrellLarkin Ovchinnikov states in orbital angular momentum space. In this letter, we demonstrate that the combined effects of spinorbitalangularmomentum coupling and level detuning can induce an exotic FuldeFerrellLarkinOvchinnikov phase, where Cooper pairs have finite centerofmass angular momenta. This implies that vortex with highvorticity can be generated without rotation or effective vector potential field. The orientation of the phase winding can be altered by adjusting the sign of level detuning. 

C71.00423: Quantum Defects in Diamond: Identifying Nitrogen Isotopes of NitrogenVacancy Centers Morgan Chamberlain, Srivatsa C Vardaraj, Zeeshawn Kazi, Elyssa B Roeder, KaiMei Camilla Fu Nitrogenvacancy (NV) centers are point defects in diamond formed by one substitutional nitrogen atom and an adjacent vacancy. Low spectral diffusion is a necessary property for NV centers to be qubit candidates. To characterize differences between naturally formed and ion implanted NV centers, diamond samples were studied that contained both types. The ion implantation used ^{15}N to be able to differentiate from the ^{14}N naturally formed NV centers. This project focused on identifying the isotope of a single NV center, which is the first step toward understanding differences in their emissive properties. Code was developed to execute, and then automate, the three experiments necessary to identify the isotope of a single NV center: Continuous Wave Optically Detected Magnetic Resonance (CW ODMR), Rabi oscillations, and Pulsed ODMR. These experiments resolve the hyperfine interaction of the nuclear spin states. The code was implemented on a test sample, where it successfully identified the isotope of several NV centers. The next step in this project is to link the isotopes of NV centers to their emissive properties, with a goal of producing reliable qubits for quantum information processing circuits. 

C71.00424: Dynamics of Inhalation Felix Kratz, JeanFrancois Louf, Anvitha Sudhakar, Nathanael Ji, Sujit Datta The process of inhalation relies on the complex interplay between muscular contraction in the thorax, elastocapillary interactions in the individual airway branches, connectivity between different branches, and overall air flow into the lungs. Sophisticated pulmonary fluid dynamics models have been developed to elaborate the competition between capillarity, which tends to keep flexible branches closed, and elasticity, which favors opening, for single airway branches. However, a quantitative model combining the physiological opening process of flexible airway branches with the biomechanics and interconnected geometry of the lungs is still missing. To address this issue, we develop a statistical model of the lungs as a symmetricallybranched network of liquidlined flexible cylinders coupled to a viscoelastic thoracic cavity. Each branch opens at a rate and a pressure that is determined by input biomechanical parameters, enabling us to test the influence of changes in the mechanical properties of lung tissues and secretions on inhalation dynamics. By summing the dynamics of all the individual branches, we quantify the evolution of overall lung pressure and volume during inhalation, and find good agreement with typical breathing curves obtained in the literature. 

C71.00425: Charge Carrier Transport in Cuprous Oxide: A Puzzle Garima Aggarwal, Sandeep K. Maurya, K. R. Balasubramaniam Deciphering the carrier transport mechanism in Cu_{2}O has been elusive, as none of the classical scattering mechanisms seems to be operative. Towards this, we study electrical properties of Cu_{2}O, wherein samples are prepared via thermal oxidation (TO), pulsed laser deposition (PLD), and electrodeposition. These methods provide a large range of grain sizes (100nm to 5mm), type of grain boundaries (high & low angle), and intrinsic defect concentration (10^{13} to 10^{18} cm^{−3}). T dependent Hall measurement is used to study carrier concentration and hole mobility. We observe the presence of two acceptor levels; a normal and a split Cu vacancy for the first time experimentally. The mobility vs. T data exhibits a maximum at 200 K for polycrystalline samples, while, monotonically decreases for single crystal and textured PLD thin film in the entire T range of study (80 – 300 K). Grain boundary (GB) scattering mechanism explains the dependence of transport at T < 200 K for samples with high angle GB. We find that trap mediated scattering is dominant for single crystal and polycrystal at T > 200 K. This suggests that instead of increasing grain size or doping, the neutralization of trap centres is the only possible way to increase the mobility and thereby, performance of Cu_{2}O based devices. 
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