Bulletin of the American Physical Society
Four Corners Section 2022 Meeting
Volume 67, Number 14
Friday–Saturday, October 14–15, 2022; Albuquerque, New Mexico
Session F01: Poster Session |
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Room: UNM PAIS 2nd Floor Mezzanine |
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F01.00001: A Thermoacoustically-Driven Vocal Tract Model Veronica Gunyan, Benjamin Miera, Abolfazl Amin, Bonnie J Andersen Over centuries, different mechanical methods have been used to mimic the sounds of the human vocal tract. Arai's three-tube sliding model is recreated to demonstrate the formant frequencies of human vowel sounds. Physiologically, this project is designed to imitate vowel formants determined by tongue position for several vowels. The source of the sound energy in this model is sound produced by heat via the thermoacoustic effect in a standing wave. The model has a sliding constriction piece that represents the tongue, a single open end to represent the mouth, and a closed end to represent the glottis. Resonances of the vocal tract act as a filter of the vocal folds and create what are called formant frequencies. Which formants resonate most strongly sheds light on how the vocal tract may promote one dominant frequency over another as determined by the tongue placement and constriction. A one-dimensional wave equation is used to calculate the formant frequencies as a function of the tongue position. By analyzing the peak frequencies from the FFT spectrum, the more dominant modes were compared to the mathematical model. The model's results can assist with speech therapy and diagnosis. |
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F01.00002: V343 Normae Orbit Fitting Hunter Chavez I present new photometry of the young binary group V343 Norma apart of the β Pictoris moving |
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F01.00003: Initialization of Binary Neutron Star Orbits Using External Potential Relaxation Scheme Michael Falato, Oleg Korobkin, Irina Sagert, Hyun Lim, Julien Loiseau Simulating neutron-star binary mergers is important for probing our knowledge of fundamental physics. Investigation into the equation of state of cold, dense nuclear matter, gaining insight into r-process nucleosynthesis during kilonovae, and gravitational-wave signal interpretation are among the many research pursuits that benefit from the numerical study of compact-star binaries with computational fluid dynamics codes. Merger simulations require accurate initial conditions in regard to the shapes of each star in orbit to correctly model the inspiral phase. In this work we demonstrate two different methods for preparing initial conditions of binary neutron-star systems for Newtonian smoothed particle hydrodynamics simulations. The first method simply assigns particle velocities based on spin, angular momentum, and separation of the stars. The binary is then evolved without the inclusion of gravitational-wave emission, i.e. at a fixed orbital distance, until the stars have relaxed to the physically correct shapes. The second method relaxes the stars within an external potential which emulates the forces experienced by the stars in a frame that is corotating with the binary. The forces deform each star to the configuration they should have given a particular spin and separation to the binary partner. We explore and compare the two different schemes e.g. in terms of their accuracy and computational efficiency. Future work will involve the application of the methods to compact-star binaries with solid components in the crust or core and their impact on the inspiral phase. |
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F01.00004: High Angular Resolution Observations of High Mass Loss Red Supergiants David T Frothingham, Ryan P Norris High mass loss occurs from the extended atmospheres of red supergiants (RSGs). RSGs are an important contributor to the chemical enrichment of the Universe. Current models of the extended atmospheres of RSGs do not agree with observations. Previous studies concluded that pulsation and convection processes alone cannot explain the mass loss behavior. Additionally, fits of effective temperatures in optical TiO bands result in poor fits in the near-infrared continuum bands, which can lead to incorrect spectral typing. Thus new semi-empirical models are necessary. We present initial optical and near-infrared interferometric observations obtained with the Center for High Resolution Angular Astronomy (CHARA) Array of the RSGs SW Cep and PZ Cas. High angular resolution interferometric observations allow us to probe the extended atmospheres and obtain precise diameters. We derive the fundamental parameters of these stars and compare their diameters at different wavelengths to test semi-empirical models of extended atmospheres. In future work we plan to extend this work to a larger sample of stars and identify molecular lines in the extended atmospheres to improve our understanding of mass loss mechanisms. |
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F01.00005: Looking for Fast Radio Bursts under 100 MHz with the Long Wavelength Array Stephanie Hansen, Jayce Dowell, Greg B Taylor Since their discovery in 2007, much effort has been devoted to uncovering both the sources of the extragalactic, millisecond-duration fast radio bursts (FRBs) and determining the limits on their emission frequencies. As telescopes gain larger fields of view and their instruments become more sensitive, our hunt for these explosive events becomes easier. We observed FRBs at the two Long Wavelength Array stations in New Mexico. The stations were triggered to observe by the CHIME/FRB project to determine if the fast radio bursts would be detectable at frequencies below 100 MHz. Between the two LWA stations we attempted to observe 72 events with no FRB detections. |
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F01.00006: Fully Dynamical General Relativistic SPH: Progress and Challenges Oleg Korobkin The method of Smoothed Particle Hydrodynamics (SPH) has a lot of appeal for simulating variety of catastrophic astrophysical scenarios, such as mergers of compact objects, tidal disruptions, etc. Conservation of angular momentum in particular is crucial in various scenarios involving stellar binaries. SPH naturally refines dense areas and avoids vacuum without need for a "density floor". With the recent detections of binary neutron star mergers GW 170817 and GW 190425 by the LIGO/Virgo collaboration, there is an increasing demand to better understand the mechanics of such mergers. Of particlar interest is the amount and composition of the neutron-rich matter ejected during the merger, as it harbors robust rapid neutron capture nucleosynthesis. |
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F01.00007: Multi-frequency observations of the PWN of Cannonball Pulsar PSR J0002+6216 Pratik Kumar, Frank K Schinzel, Greg B Taylor, Matthew Kerr, Daniel Castro, Urvashi Rau, Sanjay Bhatnagar We have made X-ray and radio observations of a newly discovered supersonic pulsar PSR J0002+6216, using Chandra and the Very Large Array (VLA), which presents a simple geometry to study the morphology of the bow shock region, and to look for evidence of in-situ particle acceleration and synchrotron cooling along the tail of the bow shock. The X-ray data provide marginal evidence for the evolution of the Pulsar Wind Nebula (PWN) emission along the tail, with spectral slope changes consistent with synchrotron cooling. Radio observations show the presence of an extended bow shock and tail region in radio continuum images, imaged using combined broad-band radio data, taken in B, C, and D configurations of the VLA. The high-resolution, long-baseline data reveal asymmetric, resolved structure around the pulsar, in the bow shock region. The radio images also show disruption of the extended tail produced by the supersonic motion of the pulsar, which points towards anomalous feature of the ISM. Based on our spectral index maps obtained within the 4-12 GHz band, the PWN shows some unusual features including an unresolved flat spectrum component. |
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F01.00008: Characterizing the Increasing Prevalence of Radio Frequency Interference at the South Pole's Dark Sector Simon Matin, Darcy Barron Radio Frequency Interference (RFI) can impact astronomical measurements when radio signals produced by artificial devices, such as cell phones and satellites, interfere with sensitive instrumentation. Instruments that are especially vulnerable to RFI can be placed in radio quiet or “dark” sites, typically remote areas where transmissions are restricted to protect instrumentation from interference. RFI can be a problem for Cosmic Microwave Background (CMB) experiments, as their technology makes them sensitive to a broad range of frequencies. As more commercial satellites are launched and as portable consumer electronic devices utilize an increasingly broad range of the electromagnetic spectrum, the prevalence of RFI is increasing, even at remote radio-quiet sites. We analyzed publicly available data collected by a dedicated RFI monitor operated by the BICEP/Keck team alongside their CMB survey instruments. This RFI monitor has run almost continuously in the South Pole’s Dark Sector since 2014, which provides a long and comprehensive record of RFI to study its prevalence by season and over time. Understanding long term trends in the prevalence of RFI can help in understanding its impact on survey sensitivity and inform future mitigation efforts. |
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F01.00009: Gas Conditions around Fading Active Galactic Nuclei. Nora C Nava, Moire K. M. Prescott, Kelly N. Sanderson Green Bean galaxies (GBs) are rare astronomical objects surrounded by luminous, spatially-extended emission line nebulae from doubly ionized oxygen ([OIII]). The strong emission, which leads to green colors in composite Sloan Digital Sky Survey imaging, is hypothesized to be ionization echoes left behind as the central Active Galactic Nuclei (AGN) faded in ionizing output over the past 10,000-100,000 years. GBs are also thought to be local, low redshift (z~0.3) cousins of the Lyα nebulae found at high redshifts (z~3), potentially giving us a window into how the gas outside galaxies evolves over time. Our goal is to investigate how the gas physical conditions of GBs compare to other AGN samples. Using spectra from the Apache Point Observatory 3.5m telescope, we estimate the gas density and temperature within GB nebulae. Contrasting the properties of AGN-powered GBs versus other AGN samples may help us understand what triggered the supermassive black hole at the center of GBs to ramp down in such dramatic fashion. |
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F01.00010: A Rarity in the Universe: MACSJ0717 Randall A Rojas Bolivar The most energetic events in the Universe since the Big Bang have been the merging of 2 galaxy clusters. In rare cases, such as with MACSJ0717, 4 subclusters have been observed to be undergoing a merger. This produces a complex merger structure with very hot (T > 20 keV) gas, only observed in clusters containing shocks with high Mach number shocks (M > 2) such as the Bullet Cluster and Abell 665. While Chandra measurements have been performed on this cluster, the constraints placed on this hot gas are inconclusive. NuSTAR's ability to probe into the hard X-ray band provides better constraints on this temperature, as well as an opportunity to constrain potential Inverse Compton (IC) scattering that may occur from the reacceleration of electrons by the shock front. |
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F01.00011: Design and manufacturing of UFOs by creating high-frequency magnetic fields or manufacturing of artificial anti-gravity Gh. Saleh Based on Saleh Theory magnetic waves have frequency in order of 1016 Hz and gravity in order of 1018 Hz. |
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F01.00012: New Calculation of the Time of the Universe from Beginning to Enda) Towards Fireb) To Coldnessc) From Big Bang to Big Bang Gh. Saleh According to the motions of the universe which includes the rotational motion that is proved by Hubble's law and that of linear which is a motion with negative acceleration, the equations of motion can be written for the universe. On the other hand, we have calculated the initial energy released from the Big Bang explosion by Monte Carlo technique, and the amounts of 10110 joules was obtained. |
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F01.00013: VLA Observations of Compact Symmetric Objects Evan Sheldahl, Greg B Taylor, Frank K Schinzel Compact symmetric objects (CSOs) are a type of radio source less than 1 kpc in size with symmetrical jet emission. They are important to study because they may have the ability to strongly influence their host galaxies and may emit radio lobes periodically through multiple epochs of activity, which can be seen on >1 kpc scales. However, they are often confused for compact steep spectrum (CSS) and gigahertz-peaked spectrum (GPS) sources in the literature due to their similarities with these types of sources and the ease of classifying them by spectra rather than morphology. To develop a more comprehensive catalog of CSOs, we have searched through about 200 publications for mentions of CSOs, CSSs, and GPSs and classified over 2000 sources as confirmed CSOs, candidates worth VLBI followup, candidates not worth followup, or rejected sources. Using the Very Large Array (VLA), we observed about 220 sources, which consists of the candidates worth VLBI followup plus some additional less likely candidate sources. In addition to using the VLA to learn more about the larger scale structure of these potential CSOs, since CSOs generally possess the ideal properties of phase calibrators at arcsecond scales, this information can be included in the VLA calibrator manual. |
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F01.00014: Finding Clear Skies in the Data from the Telescope Array Observatory Sota Nakahama The Telescope Array is located in the west desert of Utah and is the largest cosmic ray observatory in the Northern Hemisphere. The observatory employs two techniques to observe extensive air showers induced by ultra-high energy cosmic rays. The first technique is to sprinkle the desert's floor with scintillator detectors that sample the air shower's charge density when it reaches the Earth's surface. The second method utilizes fluorescence telescopes to observe the longitudinal development of the air shower via the nitrogen fluorescence light generated when the shower passes through the atmosphere. These telescopes have large mirrors which collect the shower light and focus it onto a camera made of photomultiplier tubes (PMTs). Thus, they are quite sensitive. They observe the skies over the array of scintillator detectors on clear, moonless nights. They are capable to see these showers tens of kilometers from the telescope, hence the density of clouds in the sky will affect the measurement of the shower development. Four Cloud Monitors were installed at the Middle Drum telescope station. These monitors measure the sky temperature in a 30-degree field of view using infrared sensors. In addition, telescope operators go outside and visually check the skies for clouds about once an hour. They report weather codes that quantify the direction and density of clouds in the sky. Here we analyze the correlation between the operator weather codes and the sky temperatures. |
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F01.00015: Exploration of Continental Lithospheric Mantle Evolution Using Ta/Th Ratios in Volcanic Rocks Emilyn Kracher, Mousumi Roy The ratio of tantalum to thorium (Ta/Th) in basaltic volcanic rocks has been recently proposed to be an indicator of the style of melting. Low values of Ta/Th (<0.2) are correlated with flux melting triggered by hydration, eg., subduction zones. High values (0.6 to 1.2) are correlated with decompression melting, e.g., mid-ocean ridges. The southwestern part of North America (SWNA) has undergone a transition from subduction to extension in Cenozoic time and we see variably complete transitions from low to high Ta/Th, with intermediate values (0.2 to 0.6) in-between. We analyze Ta/Th ratios vs age for basalts in spatial tiles across SWNA and characterize the observed transition in each tile by fitting a sigmoid function and noting the optimal parameters for midpoint and rate. We find a consistent transition from low to high Ta/Th across SWNA and, where extension is present, the midpoint of the transition agrees with the onset of extension. Focusing on regions that show intermediate Ta/Th, we test whether these intermediate values arise from the transport of magma through the CL (continental lithosphere). Using a 1D transport model, we show that with low transport velocity and a low diffusive constant for Th, intermediate Ta/Th can be produced even when the initial Ta/Th is not intermediate. This suggests that transport processes should be investigated in further work as they may provide clues to better understand the variability of magma-CL interactions. |
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F01.00016: Spatial and temporal correlations of thermospheric zonal winds from satellite observations Ivana M Molina, Ludger Scherliess Thermospheric neutral winds play an important role in the transport of momentum and energy in the upper atmosphere and affect the composition, dynamics and morphology of the ionospheric plasma. Although the general morphology of the winds is well understood, we are only starting to understand its variability. |
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F01.00017: Metal lift-off for fabrication of silicon nitride photonic microring resonators Gabriel M Colacion, Lala Rukh, Tara Drake Chip-scale photonic microring resonators based on Kerr nonlinearity are powerful tools for the generation of broadband optical frequency combs with applications including precision spectroscopy, low-noise frequency synthesis, and optical clocks. To support comb generation in these devices, waveguides hundreds of nanometers tall are often required. This poses a challenge for subtractive fabrication in materials such as silicon nitride (SiN), where the desired pattern is chemically etched from a solid layer of bulk material utilizing a protective mask template. While organic polymer-based masks are a common choice, they offer low resistivity to the etch process and are prone to inconsistencies in waveguide sidewall angle and depth. Alternatively, we demonstrate a novel method for subtractive processing of thick SiN waveguides with metallic chromium masks through the application of a metal lift-off technique. By leveraging the high etch resistivity of the metallic mask, we fabricate SiN microring resonators that exhibit near-vertical waveguide sidewall angles and uniform etch depth. This work serves to highlight both the benefits and drawbacks to this technique as a robust approach to achieving high-quality optical microring resonators. |
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F01.00018: Nonlinear Nano-Optics: Optical Nonlinearities of Gold Nano-Structures at the Transition from Classical to Quantum Coupling Nick D Entin, Wenjin Luo, Benjamin G Whetten, Andreij Gadelha, Fabian Menges, Markus B Raschke Understanding optical nonlinearities in nano-structures is key for novel nanospectroscopy methods and optical information processing. For Au nanostructures, the optical response from intraband electronic transitions give rise to efficient third-order nonlinear emissions, including the coherent four-wave mixing (FWM) and incoherent hot electron (HE) response. However, there is debate regarding the nano-structure incoherent emission mechanism and how it is modified by quantum effects at small interparticle separations. Emission at the separation depends on both optical quenching from near-field coupling and classical enhancement from changes in electromagnetic densities. Here, we use adiabatic nanofocusing of surface-plasmon polaritons on a Au nano-tip to investigate the FWM and HE response in the near-IR range at the transition from long-range classical resonant energy transfer to quantum coupling. We combine atomic force and scanning tunneling distance control to approach a Au surface with subnanometer precision and explore the unique optical behavior at the tunneling regime to better understand the debated emission mechanisms. We demonstrate that the classical field-enhanced behavior dominates until quantum coupling dramatically reduces emission intensity and field enhancement. |
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F01.00019: Nanoscale magnetic imaging with nitrogen vacancy centers in diamond Forrest A Hubert, Nazanin Mosavian, Janis Smits, Pauli Kehayias, Yaser Silani, Nathaniel Ristoff, Bryan A Richards, Victor Acosta We used the photoionization dynamics of nitrogen vacancy (NV) centers in diamond to perform super-resolution magnetic microscopy with a resolution approaching 50 nm. We combined a donut-based super-resolution technique with optically detected magnetic resonance measurements on dense ensembles of NV centers to enable nanoscale magnetic imaging of ~30 nm iron-oxide nanoparticles. |
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F01.00020: Balancing thermal effects for soliton stabilization in Kerr-microresonator optical frequency combs Emilio Perez de Juan, Tara Drake, Marie A Ruiz, Gabriel M Colacion, Lala Rukh Kerr-microresonators are compact, chip-scale platforms for optical frequency combs, which are lasers with many discrete and equally spaced frequencies. Unlike traditional optical frequency combs created from mode-locked lasers, Kerr-microresonator combs (microcombs) can be mass-produced on silicon wafers and allow for integration with other on-chip devices. These microresonators support solitons, a low-noise optical pulse that maintains its intensity profile and velocity indefinitely. Soliton microcombs, in contrast to the chaotic combs also supported in the microresonator, have phase-locked optical frequencies and a stable pulse train. However, soliton combs have lower intracavity powers than their chaotic precursors, and thermal instabilities caused by the abrupt change in intensity lead to short soliton lifetimes. In this work, we reduce thermal effects using a technique that allows us to sweep the wavelength of the pump light at high speeds. An intensity modulator creates sidebands on a laser, and the sideband frequency is swept faster than the thermalization time of the resonator, to reduce heating. Using a Mach-Zehnder interferometer, we characterize sideband frequency sweep rates of up to 20 MHz/ns, which is 2000 times beyond cavity-based laser tuning rates. We observe increased lifetime of the soliton state for faster sweep speeds. This is a crucial step for future designs of low-cost, compact and portable frequency combs for many different applications beyond research. |
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F01.00021: Characterizing Lasers for IPSII Interferometry Jackson A Phippen, Ulises G Thornock, Dallin S Durfee Our research group is developing a new type of lensless imaging known as Interference Pattern Structured Illumination Imaging (IPSII). IPSII uses interfering laser beams to project different patterns onto an object. IPSII requires lasers with excellent coherence to produce high visibility fringes. We are using a modified Michelson interferometer setup to test the fringe visibility produced by various lasers. We use an arduino and a photodiode to automate data collection from the fringes which we can use to compare and contrast different lasers. We can then use the data from the arduino to test whether or not a variety of lasers will be suitable for IPSII. |
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F01.00022: Micro Fabry-Perot Optical Cavities Integrated onto Atom-Chips Meagan Plummer, Spencer Olson, Matthew Marshall, Stephen Taylor, David Brown, Robert Leonard, Chandra Raman, Jacob Williamson Optical cavities are highly sensitive, versatile, and well-suited for use in ultra-fine measurements. Micro Fabry-Perot cavities can be realized using mirrors formed into the ends of optical fibers. Micro Fabry-Perot optical cavities integrated into atom-chip based magnetic traps could be used to enable enhanced atom-photon coupling for nondestructive detection and in situ optical manipulations of magnetically trapped atoms. We will present our current advancements of mechanical integration and alignment techniques for use in custom milling fiber surfaces with high precision. We have demonstrated an innovative iterative milling technique which integrates phase-shifting optical profilometry, a six-axis precision motion control stage, and a high-powered CO2 laser that ablates arbitrary surface geometries. To date, we have successfully formed concave mirrors with a 1-3 nm root-mean-square error as compared to an exact spherical surface with a radius of curvature of 1 mm. |
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F01.00023: An X-ray Spectrometer for Plasma Physics Experiments Tyler j rocha, Robert Beattie-Rossberg, Shaho Hammadamin, Salvador Portillo The University of New Mexico is developing an Xray spectrometer for plasma physics based on a commercial wavelength dispersive spectrometer. X-ray imaging plates serve as the principal detector diagnostics for X-ray emission and will be fielded in HEDP experiments such as the Z-pinch, X-pinch, and other plasma generation experiments. These diagnostics can generally be used to determine the temperature and density of a plasma; after a plasma exceeds solid state density, whereas diagnostics like heterodyne interferometry cannot provide the temperature and density information of the source. |
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F01.00024: Ultrastable Microwave Transfer of Cesium Frequency Standard over 20 km of Optical Fiber Jacob B VanArsdale, Samuel M Brewer, Dylan C Yost Tests of fundamental physics, at low temperatures in tabletop experiments, often require precise absolute frequency measurements of transitions in atomic, ionic, or molecular systems. In many cases, the accuracy of an optical frequency measurement is limited by the accuracy of the local, commercial frequency reference used in the experiment. To address this limitation in measurement accuracy, we have recently partnered with the National Institute of Standards and Technology (NIST) to establish an optical fiber link between Colorado State University and the NIST radio station, WWV, for frequency transfer of the microwave signal generated by their cesium atomic clock ensemble. This frequency transfer scheme allows the NIST (WWV) timescale to act as the absolute frequency reference for measurements taking place at CSU. We have implemented an active stabilization scheme to eliminate drifts in the optical fiber path length throughout the course of a given day. The transferred cesium signal is compared to a local Rubidium reference as a preliminary test of the stability of the link. |
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F01.00025: Time Evolution of Open Quantum Systems Toward Evolving Bio-inspired Energy Transfer Jaime A Diaz, Alexander W Hardin, Ysaris Sosa, Gregory Uyeda, Gabriel Montaño, Inès Montaño Open quantum system dynamics study time evolution of a quantum system that interacts with an environment, however, complexity of both system and environment makes exact calculations often impractical to obtain. We aim to find a reliable method relevant for studying energy transfer in long-ordered open quantum systems, polymer chlorosome nanocomposites (PCN). PCNs, artificial light harvesting systems, are an ideal candidate for studying energy transfer in open quantum system because PCNs are modifiable and exhibit efficient energy transfer over long distances. In this work, the population dynamics of four PCN systems have been simulated using the Lindbladian master equations. Each system consists of one of four types of chromophore molecule, Bchl. C,D,E,F, and are arranged in a J-like aggregate structure. Our results show how different molecules affect the energy transfer within the PCNs, and how PCN systems can be used to increase understanding of the energy transfer process. |
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F01.00026: Anomalous diffusion of RNA in the cytoplasm of HeLa cells Ryan Roessler, O'Neil Wiggan, Snehal Patil, Tim Stasevich, Diego Krapf Information about the diffusive motion of RNA would provide insights into intracellular structures and functions, as well as gene expression and genetic regulation. We study the motion of individual messenger RNA molecules in the cytoplasm of HeLa cells. RNAs are imaged in live cells via confocal, fluorescent microscopy. In order to visualize individual RNA molecules expressing the MHY9 gene, they were labeled via MS2 stem loops bound to coat proteins tagged with the HaloTag-JF646 fluorophore. We then used single-particle tracking to obtain trajectories of individual molecules. Trajectories were analyzed in terms of their mean-squared displacement (MSD) and power spectral density (PSD). We observed non-ergodic, subdiffusive behavior, with statistics that depend on observation time, i.e., aging. Additionally, we observe stochastic switching between two mobility states with an order of magnitude difference in diffusivity. This switching process is responsible for the aging nature of the system. When compared to the cytoplasmic motion of synthetic nanoparticles, the analysis of RNA trajectories gives rise to discrepancies that raise questions about specific intracellular interactions. |
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F01.00027: A multi-focus remote focusing microscope design and publication quality animation techniques for optical designs. Andrew Scheck, Tonmoy Chakraborty Remote focusing is a relatively recent improvement on fluorescence microscopy allowing for faster imaging times and greater resolution. We present two novel designs for axially swept microscopes with multiple simultaneous foci. In a previous paper, a design was shown which utilized a remote focusing in order to create a focus with variable axial position. Here, we expand upon this design to incorporate multiple focal points and multiple wavelengths. This would allow for the simultaneous imaging of multiple planes, utilizing different wavelengths of light for each plane. Two proof of concepts have been built to verify the efficacy of the designs. One demonstrates the ability to generate parallel laterally scanning foci from a single objective, while the other shows that moving a beam off axis from an objective creates an oblique focus. In addition, we show the results of a new technique for creating animations of optical setups. Using the software Blender, accurately ray traced light paths can be made which respond physically to optical components such as lenses and mirrors. Because of the physically accurate ray tracing, parts can be easily input from CAD software or manufacturers designs and can then be used to construct animations highlighting a design or concept. |
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F01.00028: Nanoporous membranes ion transport noise dynamics: Experiments match Simulations Shriram Elangovan, Vishal Nandigana Noise in nanoporous membranes and 2D based graphene nanoporous membranes is a ubiquitous phonomenon that is experimentally and theory model dynamics match is established for the first time. The theory is formulated step by step from Poisson-Nernst-Planck-Navier-Stokes model and Langevin dynamics model and matched to the time scales of experiments with the new theory dynamical model for the first time. The theory matched to the time scales for both regions of low frequency 1/f noise and high frequency noise frequencies. The results for both thick nanoporous membranes and ultrathin 2D graphene based nanoporous membranes were obtained by connecting the nanoporous membrane across bulk reservoirs of dimensions greater than few centimeters. The work makes significant leap establish of applications of nanoporous membranes in water desalination, DNA sequencing, bio-applications, ionic separation and power generator renewable energy applications. |
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F01.00029: Studying Ghosts in Field Theory with the Fully Implicit Spacetime Finite Element Method Jax G Wysong, Hyun Lim, Jung-Han Kimn In physics field theory, the term ghost refers to a system with a degree of freedom that contains a negative kinetic energy term. These systems have been deemed dynamically unstable and will evolve without bounds. However, recent studies have shown that this is not always the case: some ghost-ridden systems are dynamically stable. This research seeks to further the understanding of how different systems can survive while living with ghosts. This research was conducted by implementing numerical methods along with PETSc (Portable, Extensible Toolkit for Scientific Computation) of Argonne National Laboratory for the creation of parallel simulations. The numerical method executed here is the fully implicit space time finite element method. So far, data has been produced for cases with dimensions of 1 + 1 (one spatial and one temporal) and 2 +1. This is leading up to the 3 + 1 case which is of real interest due to its ability to represent physically realizable states of nature. |
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F01.00030: Optimizing Magnetic Domain Density in Co/Pt Ultra Thin Films Peter Krumholz, Sean Smith, Michael Vaka, Olav Hellwig, Karine Chesnel Ferromagnetic thin films exhibit magnetic domains. Magnetic domains are regions of the material where atomic magnetic moments are aligned in the same direction. Achieving a higher magnetic domain density in these ferromagnetic materials is desirable, in part because magnetic data storage could be optimized, leading to smaller computer components and higher-capacity data storage. Our group employs a variety of experimental techniques including vibrating sample magnetometry (VSM), magnetic force microscopy (MFM), and MATLAB visual analysis to visualize the domain patterns at various stages of magnetization. In particular we study the magnetic domain density in Co/Pt ultra-thin films as a function of the Co layer thickness and previously applied field. Focusing on a series of five samples each with varying layers of Co and a constant 20 repeats of layers on each, we find that the optimal domain density occurs at around 70 to 80% of the saturation field value regardless of Co thickness, which is in line with previous research. [1] |
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F01.00031: A Thermodynamic Approach to the Ideal Bose-Einstein Gas and Condensate Don S Lemons I use the quantum statistics of massive bosons and the "average energy approximation" to derive thermodynamic equations of state of an ideal Bose-Einstein gas. This thermodynamic accurately describes the main features of a Bose-Einstein gas as well as of a phase transition to a condensed state. |
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F01.00032: On the Stability of a Wormhole in the Maximally-Extended Reissner–Nordström Solution Ross DeMott, Alex Flournoy, Sam Major We consider the stability of the maximally-extended Reissner–Nordström (RN) solution in a Minkowski, de Sitter, or anti-de Sitter background. In a broad class of situations, prior work has shown that spherically symmetric perturbations from a massless scalar field cause the inner horizon of an RN black hole to become singular and collapse. Even if this is the case, it may still be possible for an observer to travel through the inner horizon before it fully collapses, thus violating strong cosmic censorship. We show that the collapse of the inner horizon and the occurrence of a singularity along the inner horizon are sufficient to prevent an observer from accessing the white hole regions and the parallel universe regions of the maximally extended RN space–time. Thus, if an observer passes through the inner horizon, they will inevitably hit the central singularity. |
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F01.00033: Treasure Hunting in the Classical Double Copy Max W Pezzelle The classical double copy relates exact solutions in general relativity with those of classical linearized Yang-Mills theory. In this poster presentation I describe the work I have done on understanding the classical double copy from various viewpoints. Using the Kerr-Schild double copy, I analyze the single copy of a rotating nonsingular black hole and analyze its horizon structure to probe the relationship between the presence of horizons on the gravity side and the single copy field on the gauge theory side. Next, I describe the mapping between the surface gravity of static spherically symmetric black holes and the force on a test particle due to the single copy field of the black hole. I also describe potential routes to extending this map to more general black holes, specifically ones which are rotating. Finally, inspired by the extended Weyl double copy for spacetimes possessing sources, I reinterpret the single copy of the Taub-NUT metric as being comprised of two terms each being sourced by a separate parameter (the mass and the NUT charge). |
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F01.00034: Characteristic Ideal GRMHD with Constraint Damping Justin C Tackett, Eric W Hirschmann, James Bleazard, Matthew R Robinson We consider the characteristic problem in ideal, general relativistic magnetohydrodynamics. Writing the relevant equations in 3+1 and balance law form, we verify the characteristic equation together with the relevant wave speeds. We provide corrections to a previous calculation of the full eigenvalue problem with complete, normalized left and right eigenvectors. We discuss extensions to include constraint damping of the magnetic monopole constraint and renormalizing the eigenvectors to handle degenerate cases. We speculate on possible applications of the full characteristic decomposition in high-resolution shock-capturing techniques and high-energy astrophysical systems such as jet launching. |
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F01.00035: Artificial Intelligence for Solving General Conformal Field Theories Anson L Kost The use of artificial intelligence (AI) in physics is burgeoning. For a few decades, machine learning has been used to tackle classification and regression problems in particle physics. More recently, AI has made an impact on the study of conformal field theory (CFT) in both applied and theoretical contexts. In particular, very recently, neural networks utilizing reinforcement learning have been applied with success to the conformal boostrap program to solve for the fundamental data of 2D CFTs. |
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F01.00036: Phase Transition and Ignition Sensitivity of Ammonium Periodate Through Density Functional Theory Calculations Armando S de Rezende, Michelle L Pantoya, Adelia A Aquino Ammonium perchlorate (NH4ClO4, APC) is a major oxidizer for civil and military applications, with efficiency and safety combustion performance. A similar material, ammonium periodate (NH4IO4, API), is extremely sensitive to friction and impact, which makes it dangerous for any application. Investigations of these materials at the atomic level provide explanations of how such similar materials can have so opposite behaviors. Density functional theory (DFT) calculations revealed small differences that imply important in consequences. The first difference is in the elastic properties, where API has a less uniform strain behavior. Although API is more rigid, with the bulk modulus (K) 25.9 GPa against 21.4 GPa for APC, the shear modulus (G) of API and APC are similar, 9.8 and 9.4 GPa respectively, implying higher Pugh’s ratio (K/G) for API, 2.65 against 2.27 for APC. Great deformations of the lattice structure are correlated with sensitivity. The most significant differences, however, are found in the electronic structure: APC is an insulator with a band gap (bg) of 6.2 eV while API is a semiconductor, with bg of only 2.9 eV. Electronic excitation is the beginning of almost any chemical reaction, and a small bg is traditionally related to the sensitivity of energetic materials. Finally, the DFT calculations indicated a phase transition in the crystalline structure of API, changing from a molecular crystal to a chained structure, with the anions (IO4-) being connected through an oxygen bridge (APIchain). This phase has an even smaller bg, only 2.09 eV, a highly reactive characteristic. The phase transition under mechanical input may trigger the decomposition. |
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F01.00037: Optical constants of bulk SrTiO3, Al2O3 on SrTiO3, and BaSnO3 on SrTiO3 using ellipsometry Yoshitha Hettige, Stefan Zollner, Suyeong Jang, Alexander A Demkov, Wente Li We measured the ellipsometric angles Ψ and △ for bulk SrTiO3 (STO) before and after cleaning (isopropanol and ozone cleaning at 150°C for 20 minutes) on a Variable Angle Spectroscopic Ellipsometer (VASE) from 0.5 to 6.6 eV with 0.01 eV steps at four different angles of incidence from 60° to 75° with a step size of 5°. We found that ozone cleaning is a better cleaning method than isopropanol. Due to the surface roughness and remaining surface layers, the imaginary part of the pseudodielectric function below the band gap of STO (3.2 eV) is positive and is used to calculate the thickness of the surface layers on STO as 19.7 Å. Using these results, we developed a VASE model for bulk STO to describe the optical constants of STO. |
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F01.00038: The design of an apparatus and methodology for testing the thermal conductivity of various materials at subkelvin temperatures katherine hewey We present the design of an apparatus and methodology for testing the thermal conductivity of various materials at subkelvin temperatures. These tests are performed using a dilution refrigerator which is commonly used to cool superconducting devices such as TES bolometers. These devices need to be cooled to very low temperatures below (0.1K) to operate properly. For operating large arrays of these devices it is necessary to reduce systematic effects in the instrumentation. One of the areas of concern is conductive heat loads between different temperature stages of the cryostat, which arise from the complex mechanical supports and cryogenic wiring supporting the focal plane and its sensors. Having precise thermal conductivity versus temperature values is vital for an accurate cryogenic model, including predicting heat loads and temperatures for each cryogenic stage. To test the thermal conductivity, heat is applied to a sample, and the temperature increase is measured. To ensure an accurate model all parasitic heat loads, such as radiative loading, have to be accounted for. This project will create a library of thermal conductance of materials at subkelvin temperatures. |
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F01.00039: Measurement of ultra-low photocurrents in metal-semiconductor-metal nanostructures: noise and sensitivity aspects Landon Schmucker, Vitaly Gruzdev, Payman Zarkesh-Ha, Wolfgang Rudolph, Luke Emmert Capability of generating electric currents and charges via direct driving free carriers of metal-semiconductor-metal nanostructures by electric field of few-cycle laser pulses promises breakthrough developments in PHz electronics, fundamental material science, characterization of laser pulses, and many other areas [1-3]. One of major challenges of this research area is the need to detect extremely low levels of laser-generated charges (about few femto-Coulombs) and currents (pico-Amps). Traditional methods of photocurrent detection fail in this case. Novel advanced approaches based on accurate analysis of noise and sensitivity of detecting units and electronic circuits are required. |
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F01.00040: A New Soft Particle Tracker for Gluon Saturation Studies at LHCb Arielle Platero, Cesar Da Silva One of the most intriguing features of Quantum Chromodynamics is the possible existence of gluon saturated matter. This theorized new state of matter would be a strong force condensate, much like the Bose-Einstein Condensates observed at the atomic level. In order to detect the effects of saturated gluons in particle colliders, a particle detector must be able to measure soft particle production in the forward direction relative to the beamline. The LHCb experiment at the LHC is an excellent candidate for detecting this potential phenomenon. The Magnet Station, a new soft particle tracking detector, has been designed for installation in the LHCb magnet. This new detector can access particles within the expected gluon saturation region. In this talk, the physics and detector concepts behind the Magnet Station, along with the development status, will be presented. |
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F01.00041: Monte-Carlo Optimization Studies of Signal and Background for a New Real Compton Scattering Experiment Proposal Austin Shipley, Austin Shipley, Michael E Paolone A proposal for a new experiment that will extract the electric and magnetic polarizabilities of the proton through Real Compton Scattering is under development. The experiment would run at the S-DALINAC in Darmstadt Germany and would use an existing Radial Time Projection Chamber (RTPC) from Jefferson Lab. The 120 MeV electron beam produced by the accelerator would be converted into photons that scatter off of a pressurized hydrogen target and the recoil protons would be detected in the RTPC. Progress from optimization studies using a Monte-Carlo simulation that aims to maximize photons on target while minimizing scattered electron backgrounds on the RTPC will be discussed at length. |
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F01.00042: Plasma Source Development for Plasma Wakefield Accelerators Ruaa Al-Harthy, Michael D Litos, Matthew Guerrero, Valentina Lee, Christopher E Doss, Claire Hansel Conventional accelerators tend to be huge to allow particles to reach velocitiess close to the speed of light. Electron driven Plasma Wakefield Accelerators (PWFA), on the contrary, provide "high gradient acceleration" which means particles can attain high speeds in significantly shorter time and distance. This allows the accelerator to be orders of magnitude smaller and therefore less expensive. In a PWFA, one electron bunch drives a strong wake in a plasma and a second electron bunch is accelerated in the plasma wake. This scheme has been shown to work, and the next research goal is to preserve the quality of the accelerated beam, which requires the correct plasma source. Research into the development of the plasma source is presented. Special optical configurations are tested that can focus a laser into a gas in order to produce the appropriate plasma density profile. |
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F01.00043: Laser Intensity Simulations for Plasma-Source Formation in a Plasma-Wakefield Accelerator Matt Guerrero, Rua'a Al-Harthy, Michael D Litos, Valentina Lee, Christopher E Doss, Claire Hansel Research conducted at SLAC National Accelerator laboratory has shown that Plasma-Wakefield Acceleration (PWFA) is a viable alternative to conventional accelerators with more favorable space and energy requirements. Plasma used in PWFA contexts is generated by using an infrared laser with extremely high peak power to ionize a gaseous medium. In a PWFA context, the plasma must be ionized along a properly-sized region, and must be the correct density to result in a favorable acceleration gradient. This is currently achieved at SLAC’s Facility for Advanced Accelerator Experimental Test (FACET-II) by shaping the incident laser profile via custom-manufactured transmissive optics. These optics are extremely thin, with microscopic diffractive gratings, which makes them extremely expensive and prone to damage. This project attempts to find a more robust alternative to these optics using off-the-shelf lenses, providing a comparable intensity profile for a much lower price. |
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F01.00044: Experimental Z Pinch Desig for Isotropic Plasma Shocks Tyler j rocha, Robert Beattie-Rossberg, Shaho Hammadamin, Salvador Portillo The University of New Mexico is beginning an investigation into parallel wire shock formation experiments to better characterize ablation rate and shocks generated from different materials. This experiment consists of multiple parallel conducting rods driven by kA currents with 100 ns rise time. The wires will ablate, creating a corona of plasma around the core of the rod. As the current increases, the ablated material is pushed inward by the Lorentz force. The Ablation flow will meet in the middle and form a shock wave traveling outward. The shock will be very dense and very hot due to large force. Initial experiments will mainly use interferometry and X-ray spectroscopy to diagnose the effect, but later experiments will have Thompson scattering and PDV diagnostics to better characterize the velocity, temperature, and density of the shock. Information about these shock experiments will give insight to shock effects in dense plasmas and information on ablation flow for future experiments. This paper presents initial design considerations for the multiwire shock experiments. |
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F01.00045: Quantum Game Theory: An Application to Quantum Information Science Michael J Brewer, Noah H Johnson, Jake Navas, Jaime A Diaz, Inès Montaño With the advent of quantum computing, there arises a need for a quantum network conducive for communication between quantum computers. In a functional system, users need to be able to reliably send information to each other without loss of information. When quantum information is sent at the same time on the same network channel, however, there is the possibility of interference, thus resulting in loss of information. In classical networks, game theory has successfully been applied to mitigate routing congestion due to its ability to find optimal strategies to increase successful outcomes in game play. In this research, we explore how quantum game theory, the fusion of game theory with quantum mechanics, can minimize congestion and optimize sending information inside a small asymmetric grid quantum network. More specifically, we investigate how the superposition and entanglement aspects of quantum mechanics can be used to increase the efficiency of routing inside a quantum network. Using the quantum network simulator, Netsquid, we test the feasibility of our approach in realistic scenarios. We quantify the benefits of applying quantum game theory to quantum routing and show how network errors can impact the probability of successful traffic control. |
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F01.00046: Using Projective Simulation And Reinforcement Learning For Quantum Circuit Discovery And Optimization Noah H Johnson, Jake Navas, M. Jaden Brewer, Manuel Guerrero, Niquo Ceberio, Inès Montaño Machine Learning (ML) algorithms are being applied in many fields and with every passing day more applications in areas such as business, healthcare, and science seem to be added to the ever-growing list. Recently, this list also started to include more and more applications from the field of quantum science, such as, e.g., quantum many-body systems, quantum optics, quantum chemistry, quantum material science, and quantum algorithms. We here investigate the potential of ML algorithms to drive progress in quantum information science, specifically quantum communication. In particular, we study if it is possible for a ML algorithm to self-learn optimal strategies for entanglement generation and long-distance distribution. High-fidelity, long-distance entanglement is a key requirement for quantum communication, specifically the realization of a long-distance quantum network (quantum internet). We will discuss our efforts to use a projective-simulation-based reinforcement algorithm to identify successful entanglement generation protocols to enable long-distance quantum communication. |
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F01.00047: Utilizing Quantum Network Simulators to Develop Methods of Quantum Network Tomography Jake Navas, Jaime A Diaz, Matheus Guedes de Andrade, M. Jaden Brewer, Noah H Johnson, Michael G Raymer, Don Towsley, Inès Montaño With recent developments in quantum computing, focus has begun to shift toward connecting quantum computers into networks. In classical computer networks, the quality of a given network is assessed using network tomography, however, an equivalent has not yet been developed for a quantum network. In order to address this need, we investigate how to assess the quality of a network by developing quantum network tomography protocols through the use of quantum simulators. Quantum network simulators provide complete network customization, allowing us to alter parameters of the network such as error rates and network topologies in order to identify characteristics of network errors. We present simulation results showing how to identify and characterize error within a quantum network. Particularly, our results indicate that it is possible to characterize common Pauli errors such as bit flips and phase flips within a network through the use of specific entangled states and user-node measurements. |
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