Bulletin of the American Physical Society
48th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 62, Number 8
Monday–Friday, June 5–9, 2017; Sacramento, California
Session D1: Poster Session I (4:00pm6:00pm)Poster

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Room: Exhibit Hall B 

D1.00001: FUNDAMENTAL CONSTANTS AND TESTS OF BASIC LAWS 

D1.00002: Total Relativistic Energy At Low Speeds Must Include Rotational and Vibrational as Well As Linear Kinetic Energies Stewart Brekke All masses will have no motion, linear, rotational and or vibrational kinetic energy. In an earlier paper it was found that the total energy a low speeds is ${E_{total}= m_0c^2 + 1/2m_0v^2 + 1/2I\omega^2 + 1/2kx^2}$. Since, according to Einstein, ${K =(m  m_0)c^2}$, the total kinetic energy of a mass at low speeds must therefore be ${K = 1/2m_0v^2 + 1/2I\omega^2 + 1/2kx^2}$. [Preview Abstract] 

D1.00003: Ongoing Work to Improve Precision Laser Spectroscopy of Helium Fine Structure. Garnet Cameron, Ronnie Currey, Khadijah Alnasser, Corey Nook, Ali Khademian, David Shiner Spectroscopy of the 2P triplet levels of helium provides a nice proving ground for various precision experimental techniques. It also provides a sensitive test of atomic theory, quantum electrodynamics and, with the isotope shift determination of the nuclear size, a test of nuclear fewbody theory. It can also provide, with improvements, an important input to the value of the fine structure constant, $\alpha $. Several improvements to our previous experiments are ongoing, including making the study of potential systematic errors more convenient by increasing the count rate. A straight forward increase results from reducing the sourcedetector separation. This is accomplished by replacing the static high voltage Efield quench plates used for the elimination of the 2S singlet background, with a more reliable and convenient laser to induce the 2S to 2P singlet resonant quenching transition at 2059 nm. We discuss the theory and performance of the 2059 nm claddingpumped Tm fiber laser we use. The inhouse fabricated Tm fiber laser has required several design iterations. Additional 1083 nm fiber lasers are being implemented to improve signal via pumping to a single m$_{\mathrm{s}}$ level ($+$1 or 1). As emphasized by Hessels and coworkers [1] for these laser transitions, nonresonant transition amplitudes often make contributions that must be included in the data analysis at current and future levels of precision. We discuss this and experimental tests of its proper inclusion. 1. A. Marsman, M. Horbatsch, and E.A. Hessels, Phys. Rev. A 86, 040501 (2012). [Preview Abstract] 

D1.00004: Preliminary results for a measurement of the n=2 Lamb shift in atomic hydrogen N. Bezginov, T. Valdez, A. C. Vutha, K. Kato, T. D. G. Skinner, E. A. Hessels We perform a measurement of the Lamb shift in atomic hydrogen (n = 2 S$_{1/2}$ F = 0 to P$_{1/2}$ F = 1). A beam of protons moving at 0.01 c undergoes charge exchange with hydrogen gas to produce atomic hydrogen in the metastable 2S state. The atoms travel through two microwave regions where we utilize the novel technique of frequency offset separated oscillatory fields (FOSOF) [PRA 92, 052504 (2015)]. The surviving 2S population is observed using a Lymanalpha detector. The outcome of this experiment will lead to a measurement of the proton radius, contributing to the resolution of the proton radius puzzle. We present preliminary experimental results, along with systematic studies. [Preview Abstract] 

D1.00005: Preliminary results for a higherprecision measurement of the helium n=2 triplet P fine structure K. Kato, T. D. G. Skinner, M. C. George, D. W. Fitzakerley, A. C. Vutha, C. H. Storry, N. Bezginov, T. Valdez, E. A. Hessels Preliminary results for a higherprecision measurement of the n=2 triplet P J=1 to J=2 finestructure interval in atomic helium are presented. A beam of metastable helium atoms is created in a liquidnitrogencooled dcdischarge source, and is intensified using a 2DMOT. These atoms are excited to the 2 triplet P state, and undergo a frequencyoffset separatedoscillatoryfield (FOSOF) [PRA 92, 052504 (2015)] microwave experiment. Only atoms which undergo a microwave transition, in the timeseparated microwave fields are laserexcited to a Rydberg state and then Stark ionized and counted. Our new experimental design has eliminated the major systematic effects of previous experiments, and has led to a substantial improvement in the signaltonoise ratio of the collected data. Our final improved measurement (with an expected uncertainty of less than 100 Hz) will allow for a test of 2electron QEDtheory in the helium n=2 triplet P system, and will be an important step towards obtaining a precise determination of the finestructure constant. [Preview Abstract] 

D1.00006: CAVITY QED WITH ULTRACOLD ATOMS 

D1.00007: Cold Atoms Inside Optical Cavity: Beyond the Semiclassical Treatment Chuanzhou Zhu, Dong Lin, Han Pu The coupling between the atomic internal pseudospin (hyperfine) states and a cavity photon field has been extensively studied in quantum optics. We include the atomic external centerofmass motion into this quantum optical system and consider the interplay of these three degrees of freedom, with the influences of the cavity pumping and dissipation included. The widely used semiclassical treatment, which neglects the atomphoton entanglement and assumes a coherent photon field, is usually adopted to study this type of atomphoton coupled systems. We examine the validity of the semiclassical treatment by comparing it with a quantum Master equation approach, and show that it is not valid under certain circumstances. [Preview Abstract] 

D1.00008: ABSTRACT WITHDRAWN 

D1.00009: TwoPhoton Blockade in an AtomDriven Cavity QED System Christoph Hamsen, Karl Nicolas Tolazzi, Tatjana Wilk, Gerhard Rempe The $n$photon blockade is a dynamical quantumnonlinear effect in which the absorption of $n$ photons blocks the absorption of the $(n+1)$th photon. This effect can occur in driven systems with an anharmonic ladder of energy eigenstates, e.g. a single atom stronglycoupled to a high finesse optical resonator. While singlephoton blockade has been demonstrated in such a system before~[1], we now report on the first observation of twophoton blockade~[2]. As a signature, we show a threephoton antibunching with simultaneous twophoton bunching observed in the light emitted from the cavity. The effect occurs for atom driving, not cavity driving. While the twolevel atom can only add photons stepwise onebyone, the bosonic enhancement for cavity driving increases the transition strengths towards higher manifolds which reduces the inherent nonlinearity of the system. We consider these results as a significant step towards multiphoton quantum nonlinear optics. \newline[1] Birnbaum et al., Nature 436,87 (2016) \newline[2] Hamsen et al., arXiv 1608.01571 (2016) [Preview Abstract] 

D1.00010: Observing Higgs and Goldstone modes in a supersolid quantum gas Philip Zupancic, Julian Leonard, Andrea Morales, Tilman Esslinger, Tobias Donner We report on the realization of a supersolid with continuous translational symmetry breaking. This U(1) invariance is engineered via symmetry enhancement by coupling a BoseEinstein condensate to the modes of two optical cavities with individual $\mathbb{Z}_2$ symmetries. Spectroscopic measurements reveal the presence of a Goldstone and a Higgs mode, and our data show their energy across the supersolid phase transition. The finite cavity leakage offers a glance into realtime dynamics of the system, while the choice of cavity detunings facilitates control of symmetrybreaking fields that tune the mass of the Goldstone mode. [Preview Abstract] 

D1.00011: Millimeterlong fiber FabryPerot cavities Torben Popplau, Konstantin Ott, S\'{e}bastien Garcia, Francesco Ferri, Ralf Kohlhaas, Klemens Sch\"{u}ppert, Romain Long, Jakob Reichel We present the realization of fiber FabryP\'{e}erot (FFP) microcavities with concave mirrors that can be operated at cavity lengths as large as 1.5 mm without significant deterioration of the finesse. This is achieved by using a laser dot machining technique to shape spherical mirrors with ultralow roughness and employing singlemode fibers with large mode area for good mode matching to the cavity. Additionally, in contrast to previous FFPs, these cavities can be used over an octavespanning frequency range with adequate coatings. We also show directly that shape deviations caused by the fiber's index profile lead to a finesse decrease as observed in earlier attempts to build long FFP cavities, and show a way to overcome this problem. Beyond concave mirror structures, the novel multipulse laser fabrication technique further allows to enlarge the range of accessible structures, including asymmetric mirror profiles, convex shapes on fiber tips and on macroscopic fused silica substrates. [Preview Abstract] 

D1.00012: Quantum ManyBody Physics with Multimode Cavity QED Varun Vaidya, Yudan Guo, Alicia Koll\'{a}r, Kyle Ballantine, Jonathan Keeling, Benjamin Lev Phase transitions, where observable properties of a manybody system change discontinuously, can occur in both open and closed systems. Ultracold atoms have provided an exemplary model system to demonstrate the physics of closedsystem phase transitions, confirming many theoretical models and results. Our understanding of dissipative phase transitions in quantum systems is less developed, and experiments that probe this physics even less so. By placing cold atoms in optical cavities, and inducing strong coupling between light and excitations of the atoms, one can experimentally study phase transitions of open quantum systems. We will report our observation of a novel form of nonequilibrium phase transition, the condensation of supermodedensitywavepolaritons. These polaritons are formed from a hybrid ``supermode" of cavity photons coupled to atomic density waves of a quantum gas. These results, found in the fewmodedegenerate cavity regime, demonstrate the potential of fully multimode cavities to exhibit physics beyond meanfield theories, possibly in the presence of dynamic synthetic gauge fields. We will also present the results of our first experiments in the fully multimode configuration. Such systems will provide experimental access to nontrivial phase transitions [Preview Abstract] 

D1.00013: Cavitymediated coherent coupling of atomic motion and spin Emma Dowd, Jonathan Kohler, Justin Gerber, Dan StamperKurn The collective motion of atomic ensembles in a cavity is well described by cavity optomechanics, while the total atomic spin precessing around an applied magnetic field exhibits analogous cavity optodynamics. For excitations around its high energy state, the spin oscillator acts as an effective negative mass oscillator, which loses energy as it gains excitations. I will present our recent work, in which we achieve cavitymediated coupling between the mechanical and spin degrees of freedom of a single ensemble of atoms. For coupling between positive and negative mass oscillators, we observe the onset of a dynamical instability caused by a nearresonant exchange of energy as both modes grow in amplitude. This coherent interaction causes dynamics similar to those of a parametric amplifier, resulting in the growth of correlations and twomode thermal squeezing. [Preview Abstract] 

D1.00014: QUANTUM PHASES AND ATOMS IN OPTIAL LATTICES 

D1.00015: Rapid onset of decoherence in drivendissipative Rydberg systems Eric Magnan, Thomas Boulier, Carlos Bracamontes, James Maslek, Jeremy Young, Alexei Gorshkov, Trey Porto, Steven Rolston Rydberg atoms have been strong candidates for the realization of quantum information processing and quantum simulation. Recently, however, there has been concerns about this approach due to the observation of a rapid onset of decoherence in large ensembles [PRA 93, 043425 (2016)]. In [PRL 116,113001 (2016)] we provide experimental support for the hypothesis that this is due to the avalanchelike onset of exchange dipole interactions, fueled by blackbody transitions to nearby Rydberg states of opposite parity. Making a fully microscopic model has proven difficult as it requires beyond meanfield arguments, but the ubiquitousness of RydbergRydberg blackbody transitions at room temperature and the alwaysresonant nature of dipole exchange interactions make it an interesting challenge, and argues for deeper study into the matter. In this poster, we present complementary measurements and analysis that confirm this mechanism. We also discuss several possibilities to reduce its impact on the system's coherence. [Preview Abstract] 

D1.00016: Quantum simulation of spin polarons with dipolar superlattice gases Lushuai Cao, Xing Deng, XueTing Fang, QianRu Zhu, ZhongKun Hu Spin polarons are under hot debate as a possible mechanism for high temperature superconducting, while the direct investigation on spin polarons remains difficult. Quantum simulation manifests itself as a promising approach for the study of spin polarons. We propose a strategy to realize effective spin polarsons with the dipolar superlattice quantum gases. In this scheme, the spin degree of freedom is modeled by the site occupation of the supercells, and the defect states are modeled by the nonoccupation or double occupation of the supercells, giving rise to hole and doublon states. We demonstrate the simulation ability of this strategy by the dynamics of annihilation of a pair of hole and doublon by emitting spin waves. [Preview Abstract] 

D1.00017: Efficient numerical technique for calculating the properties of interacting dimers in the PeierlsHubbard model John Sous, Monodeep Chakraborty, Roman Krems, Mona Berciu We develop a method to compute the Green's function for two particles in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/SuSchriefferHeeger (SSH) model. The method is based on a variational approximation to the BogoliubovBornGreenKirkwoodYvon (BBGKY)\textasciitilde hierarchy and is shown to agree with exact digaonalization calculations. We show that the properties of bipolarons arising in such models is qualitatively different from those of the wellstudied Holstein bipolarons. In particular, we show that depending on the particle statistics, strongly bound bipolarons may or may not form. In the case of hardcore bosons, we demonstrate novel effects for dimers such as sharp transitions and selftrapping. In the case of softcore particles/ spinfull fermions, we show that the mediated interactions lead to overscreeing of the bare Hubbard U repulsion resulting in the formation of strongly bound bipolarons. [Preview Abstract] 

D1.00018: Resonant interactions of Ytterbium173 in mixed confinements Luis Riegger, Nelson Darkwah Oppong, Moritz Hoefer, Immanuel Bloch, Simon Foelling Due to its earthalkaline atomic structure, fermionic $^{173}$Yb features the typical metastable excited orbital $^3\mathrm{P}_0$, connected to the ground state orbital via an ultranarrow clock transition. The zero angular momentum states additionally feature a strong decoupling of nuclear spin and electronic state. The particular isotope $^{173}$Yb features a nearresonant molecular bound state, leading to a Feshbach resonance between the two orbital states. We trap both atomic orbitals in statedependent optical lattices with different AC polarizabilities, pinning the excitedstate atoms while tunneling remains possible for the groundstate atoms. We investigate the resulting two and fewbody interactions in systems with separate confinement and dimensionality, which influence the effective interactions in the manybody system. These interactions in a statedependent lattice configuration emulate a version of the twoorbital Kondo and Kondolattice model with unusual spin interactions. [Preview Abstract] 

D1.00019: Engineering quantum dimer models via largespin Mott insulating ultracold bosons Bhuvanesh Sundar, Todd Rutkowski, Michael Lawler, Erich Mueller We propose an experimental protocol to produce quantum dimer models using ultracold bosonic atoms with a large hyperfine spin confined in a deep optical lattice. We explain how an optical Feshbach resonance can control the strength of interactions in different spin channels, leading to a limit where the lowenergy Hilbert space is defined by nonoverlapping shortrange dimers. Solving this model in different lattice geometries yields the columnar phase on a square lattice and the $\sqrt{12}\times\sqrt{12}$ phase on a triangular lattice. The ground state is unknown on a cubic lattice. We give protocols to measure dimerdimer correlations in the ground state using photoassociation and quantum gas microscopy. Experimentally implementing our proposal would allow us to explore models that have a long history in condensed matter physics, and experimentally resolve theoretically unknown phase diagrams in threedimensional lattices. [Preview Abstract] 

D1.00020: Meanfield scaling of the superfluid to Mott insulator transition in a 2D optical superlattice. Masayuki Okano, Claire Thomas, Thomas Barter, TszHim Leung, GyuBoong Jo, Jennie Guzman, Itamar Kimchi, Ashvin Vishwanath, Dan StamperKurn Quantum gases within optical lattices provide a nearly ideal experimental representation of the BoseHubbard model. The meanfield treatment of this model predicts properties of nonzero temperature latticetrapped gasses to be insensitive to the specific lattice geometry once system energies are scaled by the lattice coordination number z. We examine an ultracold Bose gas of rubidium atoms prepared within a twodimensional lattice whose geometry can be tuned between two configurations, triangular and kagome, for which z varies from six to four, respectively. Measurements of the coherent fraction of the gas thereby provide a quantitative test of the meanfield scaling prediction. We observe the suppression of superfluidity upon decreasing z, and find our results to be consistent with the predicted meanfield scaling. These optical lattice systems can offer a way to study paradigmatic solidstate phenomena in highly controlled crystal structures. [Preview Abstract] 

D1.00021: Measuring correlations in attractive and repulsive FermiHubbard systems with a lithium quantum gas microscope Peter Schauss, Peter Brown, Debayan Mitra, Elmer GuardadoSanchez, Waseem Bakr Quantum gas microscopes have taken the study of Hubbard physics in optical lattices to a new level, enabling siteresolved detection of strongly correlated states like Mott insulators and antiferromagnets. We present two experiments where we use a lithium6 quantum gas microscope to study the Hubbard model in new regimes. In a first experiment we investigate the spin correlations of the repulsive Hubbard model in the presence of spinimbalance. We observe shortrange canted antiferromagnetism by measuring the anisotropy of spin correlations in two bases. In addition we find nonmonotonic behavior of the spin polarization with doping resembling the behavior of the magnetic susceptibility in the cuprates. In another experiment, we observe charge density wave correlations in the attractive Hubbard model at half filling. These correlations provide a lowtemperature thermometer for the attractive Hubbard model and allow indirect measurement of superfluid correlations in this system. [Preview Abstract] 

D1.00022: Detection of antiferromagnetic order and characterizing spincharge separation with ultracold $^6$Li in a compensated optical lattice YaTing Chang, Zhenghao Zhao, TsungLin Yang, ChungYou Shih, Randall Hulet We explore the physics of fermions in both 1D and 3D using ultracold $^6$Li atoms in an optical lattice. We have realized the 3D FermiHubbard model and detected shortrange antiferromagnetic (AFM) spin correlations via Bragg scattering\footnote{R. A. Hart, P. M. Duarte et al., Nature 519, 211214 (2015).}. We must cool to 40\% lower temperatures to realize the longrange ordered N$\acute{e}$el phase. We are setting up a low noise laser and servo to reduce the rate of heating by lattice intensity fluctuation. In addition, we are studying the 1D system by turning off one of the lattice beams. Luttinger liquid theory predicts that fermions have different speeds of sound for spin and charge excitations, an effect known as spincharge separation. Evidence of spincharge separation has been obtained in quantum wire tunneling experiments\footnote{O. M. Auslaender et al., Science 308, 88 (2005).}$^,$\footnote{Y. Jompol et al., Science 325, 597 (2009).}. However, spin and charge dispersion have not been measured independently. Ultracold atoms provide a highly tunable system for which we may directly observe this phenomenon using Bragg spectroscopy\footnote{S. Hoinka et al., Phys. Rev. Lett. 109 , 050403 (2012).}. [Preview Abstract] 

D1.00023: Exploring longrange antiferromagnets with singlesite resolution Christie S. Chiu, Anton Mazurenko, Geoffrey Ji, Maxwell F. Parsons, Marton KanaszNagy, Richard Schmidt, Fabian Grusdt, Eugene Demler, Daniel Greif, Markus Greiner Quantum gas microscopy of ultracold fermionic atoms in optical lattices opens new perspectives for addressing longstanding open questions on strongly correlated lowtemperature phases in the Hubbard model such as doped antiferromagnets. Using siteresolved potential engineering for improved cooling, we demonstrate longrange antiferromagnetic order extending over our entire sample, a disk extending ten sites across filled with a twocomponent spin mixture of ultracold fermionic Li6 atoms in a square lattice. We measure the siteresolved spin correlation function and find the correlation length to be comparable to the system size. The order is also detected from a sharp momentum peak in the spin structure factor and the onset of a nonzero staggered magnetization. We further explore the phase diagram of the Hubbard model by studying magnetic order when doping the system away from halffilling – a regime where precise numerical studies become challenging. We additionally discuss our progress towards achieving order for larger system sizes and observing the dynamics of a deterministically placed hole in spin backgrounds of varied magnetic order. [Preview Abstract] 

D1.00024: Progress Towards Spectroscopy of Pairs in the Attractive FermiHubbard Model Wenchao Xu, William Morong, Brian DeMarco The capability to tune interparticle interactions via a Feshbach resonance makes ultracold fermionic atoms trapped in optical lattices an ideal platform to study the attractive Fermi Hubbard model, which is difficult to realize in conventional solidstate systems. Theory indicates that pairs can form in the lattice with a coherence length controlled by the interaction strength. As the coherence length becomes comparable to lattice spacing, a crossover between BCSlike pairing and a BEClike bound state occurs. We present progress on spectroscopy measurements of the pair binding energy in the BECBCS crossover regime and compare with theory. We discuss how we can use an optical speckle potential to study the effect of disorder on the pair spectrum, which has not been fully resolved by current theoretical approaches. [Preview Abstract] 

D1.00025: Quantum Gas Microscope for Fermionic $^{\mathrm{40}}$K Melih Okan, Matthew Nichols, Lawrence Cheuk, Hao Zhang, Martin Zwierlein In this poster, we present the recent experimental progress on our quantum gas microscope for fermionic $^{\mathrm{40}}$K. We show our findings on insitu studies of metallic, Mott insulating, and band insulating states of the two dimensional (2D) FermiHubbard model as well as the extension of these studies to explore spatial charge and spin correlations using spinsensitive fluorescence imaging of ultracold 40 K atoms trapped in a square optical lattice. Subsequently, we report on furthering these studies of spatial correlations to lower temperatures. [Preview Abstract] 

D1.00026: Magnetic order by adiabatic demagnetization for fermions in an optical lattice Anthony E. Mirasola, Michael L. Wall, Kaden R. A. Hazzard The FermiHubbard model describes ultracold fermions in an optical lattice and exhibits antiferromagnetic longranged order below the Neel temperature. However, reaching this temperature in the lab has remained an elusive goal. In other atomic systems, such as trapped ions, low temperatures have been successfully obtained by adiabatic demagnetization, in which a strong effective magnetic field is applied to a spinpolarized system, and the magnetic field is adiabatically reduced to zero. There is a fundamental obstacle to applying this approach to the FermiHubbard model: it possesses an SU(2) symmetry that introduces many level crossings which prevent the system from adiabatically reaching the FermiHubbard ground state, even in principle. However, by breaking the SU(2) symmetry with a spindependent tunneling, we point out that adiabatic demagnetization can in principle achieve low temperature states. Such spin dependent tunnelings can be engineered by multiple techniques. Using density matrix renormalization group (DMRG) calculations in one dimension, we numerically find that for sufficiently slow demagnetization protocols, low temperature states can be reached, and we will describe how to optimize this protocol to be experimentally viable. [Preview Abstract] 

D1.00027: Antiferromagnetic spinor condensates in a bichromatic superlattice Tao Tang, Lichao Zhao, Zihe Chen, Yingmei Liu A spinor BoseEinstein condensate in an optical supelattice has been considered as a good quantum simulator for understanding mesoscopic magnetism. We report an experimental study on an antiferromagnetic spinor condensate in a bichromatic superlattice constructed by a cubic reddetuned optical lattice and a onedimensional bluedetuned optical lattice. Our data demonstrate a few advantages of this bichromatic superlattice over a monochromatic lattice. One distinct advantage is that the bichromatic superlattice enables realizing the firstorder superfluid to Mottinsulator phase transitions within a much wider range of magnetic fields. In addition, we discuss an apparent discrepancy between our data and the meanfield theory. [Preview Abstract] 

D1.00028: QUANTUM GASES IN LOW DIMENSIONS 

D1.00029: Transport Properties of Bright MatterWave Dipolar Solitons in a TonksGirardeau gas Matthew Edmonds, Thomas Busch The dynamics of manybody systems can often be reduced to a particle analogy, leading to rich insight into their behaviour. In the onedimensional limit the TonksGirardeau gas [1,2] has been realized, where strong repulsive interactions dominate the system dynamics. The creation of condensates with atoms possessing significant dipoledipole interactions [3] heralds a novel avenue in the Ultracold landscape for the study of nonlinear waves, such as bright solitons whose interactions are intrinsically attractive. We investigate the transport properties of a TonksGirardeau gas with a bright soliton, for realistic geometries. We study the dynamics and equilibration of these two systems, which we quantify in terms of the strength of their mutual coupling. The dynamics are found to depend on the initial conditions, and are increasingly anharmonic as the strength of the coupling is increased, leading to the identification of different dynamical regimes. [1] B. Paredes, A. Widera, V. Murg, O. Mandel, S. F\"olling, I. Cirac, G. V. Shlyapnikov, T. W. H\"ansch, and I. Bloch, {\bf 429}, 277 (2004). [2] T. Kinoshita, T. Wegner, D. S. Weiss, {\it Science} {\bf 305}, 1125 (2004). [3] T. Lahaye, C. Menotti, L. Santos, M. Lewenstein, and T. Pfau, {\it Rep. Prog. Phys.} {\bf 72} 126401 (2009). [Preview Abstract] 

D1.00030: Progress towards a quantum simulator based on ultracold strontium Wei Qi, Mingcheng Liang, Xibo Zhang Realizing ultracold atoms in the fractional quantum Hall regime has been challenging because of difficulties in suppressing heating and loss due to spontaneous emission and in preparing and manipulating ultracold samples with very small atom numbers. Owing to its ultranarrow clock transition, $^{\mathrm{87}}$Sr has become a promising candidate to overcome these difficulties. We report experimental progress towards building a quantum simulator that, on the basis of fermionic strontium 87, uses Raman optical lattices to engineer synthetic gauge fields and induce nontrivial topological flatbands. Microscopy with micrometer resolution and coherent spectroscopy based on an ultrastable clock laser can be integrated into the apparatus for manipulating and measuring novel strongly correlated quantum systems. [Preview Abstract] 

D1.00031: Measuring the Speed of Sound in a 1D Fermi Gas Jacob Fry, Yi Jin, Anna Marchant, Randall Hulet We have undertaken measurements of the speed of sound in a twospin component, 1D gas of fermionic lithium. The 1D system is an array of onedimensional tubes created by a 2D optical lattice. To measure the speed of sound, we create a localized density perturbation at the center of the atom cloud using a sheet of light. Depending on the laser's frequency, the atoms feel either a spinsensitive or insensitive force\footnote{A. Recati, P. O. Fedichev, W. Zwerger, and P. Zoller, Phys. Rev. Lett. 90, 020401 (2003).}. Once the lightsheet beam is turned off, the density perturbation propagates to the edge of the atomic cloud with a velocity that depends on the strength of interatomic interactions, which we control using a magneticallytuned Feshbach resonance. This method may be used to extract the Luttinger parameter vs. interaction strength. We will report our progress. [Preview Abstract] 

D1.00032: Detecting The FFLO Phase In The Dimensional Crossover Of An Imbalanced FERMI Gas Yi Jin, Jacob Fry, Anna Marchant, Melissa Revelle, Randall Hulet The exotic FuldeFerrellLarkinOvchinnikov (FFLO) magnetized superconductor occupies a large region of the onedimensional (1D) phase diagram. However, the FFLO phase is more robust against quantum and thermal fluctuations in higher dimensions. This motivated us to map the dimensional crossover between 1D and 3D\footnote{M. C. Revelle et al. Phys. Rev. Lett. 117, 235301 (2016).}, as it is predicted to be the optimal regime to search for FFLO\footnote{M. M. Parish et al. Phys. Rev. Lett. 99, 250403 (2007).}. We prepare a spinimbalanced Fermi gas of $^6$Li, analogous to creating a magnetized atomic cloud. By using a 2D optical lattice, we confine the atoms to 1D tubes and bring the system to the dimensional crossover regime by tuning the intertube tunneling rate and interaction strength. To detect FFLO, we take 1D time of flight measurements using a bluedetuned antitrapping beam to cancel the axial confinement. This permits the mapping of the linear momentum distribution, from which signatures of FFLO may be observed. [Preview Abstract] 

D1.00033: Coherence of strongly interacting 2D quantum gases Lennart Sobirey, Jonas Siegl, Niclas Luick, Klaus Hueck, Thomas Lompe, Henning Moritz The dimensionality of a quantum system has a profound impact on its coherence and superfluid properties. In 2D systems true longrange coherence is precluded by thermal fluctuations, nevertheless they can still become superfluid as predicted by Berezinskii, Kosterlitz and Thouless. In this superfluid regime the first order coherence decays algebraically, free of any characteristic length scale. Here, we show coherence measurements in a strongly interacting 2D gas of diatomic $^{6}$Li molecules. A selfinterference technique allows us to locally extract the algebraic decay exponent, which is directly linked to the superfluid density. Furthermore, we present our realization of a homogeneous ultracold 2D Fermi gas. It should enable the direct measurement of nonlocal quantities such as the momentum distribution, without the complication of averaging over the different densities present in a harmonic trap. [Preview Abstract] 

D1.00034: Ring and ring lattice trapping potentials for quantum manybody experiments with lithium Daniel Allman, Yanping Cai, Kevin Wright Multiplyconnected geometries (e.g. rings) provide a natural setting for studying transport properties of unusual quantum phases of matter. Preciselyconstructed optical traps can provide such a setting to study novel collective behavior in 1D periodic geometries. We have designed and tested an integrated optical system for creating stable and wellstructured ring traps and ring lattices for use at multiple laser wavelengths. The system uses amplitude masks, phase imprinting techniques, and the adjustment of aperture stops to control the shape of the projected optical trapping potentials. [Preview Abstract] 

D1.00035: SPINOR GASES AND MAGNETIC PHENOMENA 

D1.00036: Preserving squeezed spin states of a spin1 BoseEinstein condensate with rotary echoes Wenxian Zhang, Jun Zhang, Yingying Han, Peng Xu A challenge in precision measurement with squeezed spin state arises from the spin dephasing due to stray magnetic fields. To suppress such environmental noises, we employ a continuous driving protocol, rotary echo, to enhance the spin coherence of a spin1 BoseEinstein condensate in stray magnetic fields. Our analytical and numerical results show that the squeezed spin states are preserved for a significantly long time, compared to the free induction decay time, if the magic condition $h\tau = m\pi$ is met with $h$ the pulse amplitude and $\tau$ pulse width. In particular, both the spin average and the spin squeezing, including the direction and the amplitude, are simultaneously fixed for a squeezed spin state. Our results provide a practical way to implement quantum measurements based on a spin1 condensate utilizing a squeezed spin state. [Preview Abstract] 

D1.00037: Manipulation of heteronuclear spin dynamics with microwave and vector light shift Lintao Li, Bo Lu, Bing Zhu, Dajun Wang We report the study of heteronuclear spinexchange dynamics starting from a spin1 mixture of Rb\textbar 1,0\textgreater and Na\textbar 1,0\textgreater atoms. which depends on the competition between the Zeeman energy and interspecies spindependent interaction energy. Within a narrow magnetic field window around 1 G, we have observed a dramatic enhancement of a particular process: Rb\textbar 1,0\textgreater $+$ Na\textbar 1,0\textgreater $\Leftrightarrow $ Rb\textbar 1,1\textgreater $+$ Na\textbar 1,1\textgreater . We also demonstrated the ability to precisely manipulate this process via a fardetuned microwave or laser field. The microwave method, similar to that in singlespecies spinor gases, tunes the speciesselective quadratic Zeeman energy. As a comparison, the light field shifts the speciesdependent linear Zeeman energy. Both methods are shown to be powerful and flexible in our system. Our investigations have revealed the richness of quantum manipulations in heteronuclear spinor systems. [Preview Abstract] 

D1.00038: Improved Apparatus to Study MatterWave Quantum Optics in a Sodium Spinor BoseEinstein Condensate Shan Zhong, Anita Bhagat, Qimin Zhang, Arne Schwettmann We present and characterize our recently improved experimental apparatus for studying matterwave quantum optics in spin space in ultracold sodium gases. Improvements include our recent addition of a 3Dprinted Helmholtz coil frame for field stabilization and a crossed optical dipole trap. Spinexchange collisions in the $F=1$ spinor BoseEinstein condensate can be precisely controlled by microwave dressing, and generate pairs of entangled atoms with magnetic quantum numbers $m_F=+1$ and $m_F=1$ from pairs of $m_F=0$ atoms. Spin squeezing generated by the collisions can reduce the noise of population measurements below the shot noise limit. Versatile microwave pulse sequences will be used to implement an interferometer, a phasesensitive amplifier and other devices with subshot noise performance. With an added ion detector to detect Rydberg atoms via pulsefield ionization, we later plan to study the effect of Rydberg excitations on the spin evolution of the ultracold gas. [Preview Abstract] 

D1.00039: Spinor Dynamics Of A Freely Expanding F=1 BoseEinstein Condensate Zachary Glassman, Donald Fahey, Arne Schwettmann, Jonathan Wrubel, Paul Lett Spinexchange collisions drive coherent population oscillations between $m_F$ ground states in an optically trapped $F=1$ BoseEinstein condensate that depend on the density and quadratic Zeeman shift. Due to the slow expansion of the condensate, spinor dynamics persist after release from the trap when timeofflight detection is used, and the changing density during free expansion must be factored into the analysis, particularly if the effective magnetic field is changed during this time. The recent adoption of microwave dressings in spinor BEC experiments has improved the control over the quadratic Zeeman shift, $q$, and allowed for negative shifts and fast switching times for quench experiments. By switching the parameter $q$ at a variable time during the free expansion of a sodium $F=1$ BoseEinstein condensate, the effects of a changing density and magnetic field on the spinor evolution were investigated. Our measurements agree well with a meanfield simulation under the singlemode approximation, and both experimental and simulation data are presented. [Preview Abstract] 

D1.00040: COLD AND ULTRACOLD MOLECULES 

D1.00041: Internal state control of a dense sample of ultracold $^{\mathrm{23}}$Na$^{\mathrm{87}}$Rb molecules Xin Ye, Mingyang Guo, Junyu He, Dajun Wang, Goulven Quemener, Maykel GonzalezMartinez, Oliver Dulieu We report the optimized production of ultracold $^{\mathrm{23}}$Na$^{\mathrm{87}}$Rb molecules with completely controlled population distribution among internal states. Starting from a sample of 10$^{\mathrm{4}}$ weakly bound Feshbach molecules, we achieved a hyperfinestructureresolved STIRAP transfer to the ground state with an efficiency up to 95{\%}. By tuning the frequency difference between the Raman lasers and applying an additional microwave signal, we realized the preparation of NaRb samples in different vibrational, rotational, and hyperfine levels. Based on this achievement, some results on molecular collisions with a range of possible loss channels will also be reported. [Preview Abstract] 

D1.00042: Lowenergy excitations of a BoseEinstein condensate of rigid rotor molecules Joseph Smith, Evan Jones, Seth Rittenhouse, Ryan Wilson, Brandon Peden We investigate the properties of the ground state and lowlying excitations of an oblate BoseEinstein condensate composed of rigid rotor molecules in the presence of an external polarizing electric field. We build in a quantum model of molecular polarizability by including the full manifold of rotational states. The interplay between spatial and microscopic degrees of freedom via feedback between the molecular polarizability and intermolecular dipoledipole interactions leads to a rich quasiparticle spectrum. Under large applied fields, we reproduce the wellunderstood densitywave rotonization that appears in a fully polarized dipolar BEC, but under smaller applied fields, we predict the emergence of a spin wave instability and possible new stable ground state phases. [Preview Abstract] 

D1.00043: Towards laser cooling and trapping of barium monohydride Rees McNally, Geoffrey Iwata, Marco Tarallo, Tanya Zelevinsky We report progress towards the laser cooling of diatomic BaH, demonstrating operation of a cryogenic buffer gas beam source with a brightness of $10^6  10^7$ molecules in the trapping region per ablation pulse, the brightest hydride beam to our knowledge. This source has enabled studies of the transitions and properties of BaH relevant to laser cooling, and we show preliminary results towards optical manipulation. Looking forward, plans for chirped molecular slowing on the A $\Sigma$ excited state, followed by magnetooptical trapping on the B $\Sigma$ excited state will be presented. Finally, we discuss the feasibility of photodissociation of ultracold BaH as a source of dilute ultracold hydrogen suitable for precision spectroscopy, a unique application for the monohydrides. [Preview Abstract] 

D1.00044: BoseEinstein condensate of rigid rotor molecules Evan Jones, Joseph Smith, Seth Rittenhouse, Brandon Peden, Ryan Wilson We study the ground state phases of a quasitwodimensional BoseEinstein condensate (BEC) of dipolar rigid rotor molecules subject to a DC electric field. In the highfield limit, this system acquires the properties of the fully polarized dipolar BEC, which exhibits a rotonmaxon excitation spectrum, and has been thoroughly studied in the theoretical literature. In the weakfield limit, however, qualitatively new physics emerges due to the competition between the (weak) applied field and internal electric fields, which are produced by the molecules themselves. We characterize the ground states of this system, and study its unique dielectric properties. [Preview Abstract] 

D1.00045: Cold KCa$^{\mathrm{+}}$ interaction studies in an ionatom hybrid trap Jyothi Saraladevi, Kisra Egodapitiya, Gang Shu, Bichen Zhang, John Condoluci, Piero Chiappina, Di Lao, Zhubing Jia, Rob Clark, Ken Brown Mixtures of cooled and trapped ions and atoms enable study of cold collisions including elastic collisions, charge exchange interactions and molecular ion formation. To facilitate these studies, we have developed an apparatus comprising a spatially overlapped ion trap (linear Paul trap) and an atom trap (magneto optical trap) [1]. The apparatus is integrated with a high resolution time of flight mass spectrometer for identifying the reaction products. Initial studies on interactions between cold Calcium (Ca$^{\mathrm{+}})$ ions and Potassium (K) atoms will be presented. The prospects for rotational cooling of molecular ions by interaction with ultracold Potassium atoms will be discussed. [1] Wade G. Rellergert, Scott T. Sullivan, Steven J. Schowalter, Svetlana Kotochigova, Kuang Chen {\&} Eric R. Hudson, Nature 4 9 5, 490 (2013) [Preview Abstract] 

D1.00046: Weakly bound molecular ions with giant electric dipole moment and polarizability Michal Tomza, Krzysztof Jachymski We investigate molecular ions in weakly bound rovibrational states and show that they have a giant permanent electric dipole moment with a value up to 1000$\,$Debye and a giant electric dipole polarizability with a value up to $10^{15}\,a_0^3$. Using quantum defect theory we derive analytic expressions for these properties as functions of binding energy. We show that the electric properties and radiative lifetimes of weakly bound molecular ions can be controlled with a magnetic field via magnetically tunable Feshbach resonances, whereas the magnetic properties can be controlled with a laserinduced Stark effect. Thus, these systems constitute an interesting example with a controllable interplay between electric and magnetic interactions. We analyze practical implications of our findings and propose new ultracold precision measurement experiments to access the unusual properties of the investigated systems. [Preview Abstract] 

D1.00047: A twospecies quantum gas experiment for the preparation of ultracold polar NaK molecules Torben Schulze, Torsten Hartmann, Kai Voges, Alessandro Zenesini, Silke Ospelkaus Ultracold mixtures of atomic quantum gases provide the starting point for the preparation of polar ground state molecules, which are excellent candidates for the study of quantum chemistry and exotic dipolar quantum phases. Here, we present an experimental apparatus for the preparation of ultracold Na and K quantum gas mixtures, which are two favorable candidates for a mixture experiment due to the wellknown cooling strategies for the individual atoms. We describe our experimental setup including a high resolution objective providing an experimentally verified resolution of 700nm and a versatile electrode configuration for the manipulation and control of molecules in external electric fields. We present our approach towards the preparation of quantum degenerate mixtures, our measurements regarding the uptonow unknown scattering properties of the bosonboson mixture and our envisioned pathway for the efficient conversion of NaK Feshbach molecules into ground state molecules. [Preview Abstract] 

D1.00048: Characterisation of a magnetooptical trap for CaF molecules Stefan Truppe, Jack Devlin, Hannah Williams, Moritz Hambach, Luke Caldwell, Noah Fitch, Ben Sauer, Ed Hinds, Mike Tarbutt We present a detailed characterization of a magnetooptical trap (MOT) of CaF molecules. We capture approximately $2.2\times10^4$ molecules in the MOT from a buffer gas molecular beam which is slowed via radiation pressure. At the highest laser intensity, the lifetime of the molecules in the MOT is about 100ms, the trap frequency is 94Hz and the damping coefficient is 390(4)s$^{1}$. The molecules reach an equilibrium temperature of 12mK which is nearly 50 times higher than the Doppler limit. We explore how the scattering rate, trap frequency, damping coefficient and temperature depend on the intensity. We compare our results to standard Doppler cooling theory and to an advanced model that takes into account the effect of polarization gradients. [Preview Abstract] 

D1.00049: Implementation of invacuum electrodes for manipulating interactions between ultracold KRb molecules Kyle Matsuda, Jacob Covey, Luigi De Marco, William Tobias, Giacomo Valtolina, Jun Ye Ultracold molecules represent an ideal platform for studying manybody physics with longrange dipolar interactions. The field of ultracold polar molecules has recently made enormous progress and many different bialkali molecules have been produced in their ground state. Recently, dipolar spinexchange interactions and manybody dynamics have been observed with Fermionic KRb molecules in an optical lattice, and lowentropy samples in a lattice have been realized. However, the ability to apply large electric fields to polarize the molecules has been limited to several kV/cm. Additionally, high resolution in situ has been lacking for polar molecules despite the enormous progress in the quantum gas field. We present a new apparatus for producing Fermionic KRb molecules where stable, homogeneous electric fields in the range of 30 kV/cm are expected, while also accommodating arbitrary gradients in two dimensions. This apparatus is designed for high resolution addressing and detection, and imaging resolutions well below 1 micron are expected. We present details on this apparatus and its construction, and describe the procedure used to produce ultracold gases of atoms and molecules. Further work will lead to high resolution detection of strongly dipolar quantum systems. [Preview Abstract] 

D1.00050: Ultra cold $^{\mathrm{23}}$Na$^{\mathrm{40}}$K molecules in Munich  d/D route to the ground state NaK molecule XinYu Luo, Frauke Seeßelberg, Nikolaus W. Buchheim, Zhenkai Lu, Immanuel Bloch, Christoph Gohle Ultracold polar molecule gases are a promising quantum system to investigate strongly interacting manybody models with longrange interactions like the tJ model and explore novel phases of quantum matter such as fractional Mott insulators and supersolids. We report on the ongoing efforts to create an ultracold, polar NaK gas in Munich. Our setup features open optical access, e.g. for highresolution imaging or optical lattices, and can reliably produce ultra cold mixtures of sodium and potassium. Recently we succeeded to produce ultracold $^{\mathrm{23}}$Na$^{\mathrm{40}}$K molecules. To that end we transfer weakly bound Feshbach molecules to the electronic and rovibronic molecular ground state using stimulated Raman adiabatic passage. We employ the d$^{\mathrm{3}}\Pi (\nu =$ 5$, J=$ 1$, \Omega =$ 1) as intermediate state which mixes with the D$^{\mathrm{1}}\Pi $ electronic state via spin orbit interaction. The properties of the ground state such as its lifetime and polarizability are discussed. [Preview Abstract] 

D1.00051: Ultracold 4center reactions of KRb molecules. MingGuang Hu, Yu Liu, Andrei Gheorghe, YenWei Lin, KangKuen Ni Chemical reactions at the fundamental level obey the laws of quantum mechanics. However, reactions are often far from the regime where the quantum motions of the reagents play an important role. Ultracold reactions of KRb is a good candidate, where the unusual 4center reactions between two KRb molecules is expected to produce K2 and Rb2 molecules with 10 {\$}cm\textasciicircum \textbraceleft 1\textbraceright {\$} (or 14.4 K) excess energy. To directly measure reaction products and to fully map out their quantum states, we are designing and constructing a novel quantum degenerate gas apparatus with the integration of REMPI and ion velocity mapping imaging. Our work aims to open up new directions for physical chemistry studies with AMO techniques. [Preview Abstract] 

D1.00052: Genetic based fitting techniques for potential energy curves of diatomic molecules Ian Stevenson, Jesus PerezRios, Dan Elliott We present development of a genetic algorithm for fitting potential energy curves of diatomic molecules to experimental data. Our program takes in a `guess' potential, often from an \textit{ab initio} calculation, along with experimental measurements of vibrational binding energies, rotational constants, and the experimental uncertainty. The fitting program is able modify the guess potential until it reproduces the experimental data with better than 1\% uncertainty. We present the details of this technique along with a comparison of potentials calculated by the genetic algorithm and by an inverted perturbation approach for the $X \ ^1\Sigma^+$ potential of lithiumrubidium. [Preview Abstract] 

D1.00053: Hyperfine structures of the $B^{\mathrm{1}}\Pi $, $c^{\mathrm{3}}\Sigma ^{\mathrm{+}}$, and $b^{\mathrm{3}}\Pi $ states of ultracold$^{\mathrm{\thinspace 85}}$Rb$^{\mathrm{133}}$Cs via short range photoassociation JinTae Kim, Toshihiko Shimasaki, Yuqi Zhu, David DeMille Shortrange photoassociation (PA) has opened up to investigate various hyperfine structures of deeply bound rovibrational levels of the strongly perturbed $B^{\mathrm{1}}\Pi $, $c^{\mathrm{3}}\Sigma^{\mathrm{+}}$, and $b^{\mathrm{3}}\Pi $ states with high resolution of \textasciitilde 10 MHz. Peculiar potential curves of the electronic states with crossings and inflections obtained from Fouriertransform spectroscopy (FTS) with low resolution of 900 MHz [1] give strong evidences for strong spinorbit coupling effects between the singlet and triplet states. We have observed new shortrange PA lines of the $B^{\mathrm{1}}\Pi (\Omega =$1), $b^{\mathrm{3}}\Pi (\Omega =0^{}$, 0$^{\mathrm{+}}$, and 1), and 3$^{\mathrm{3}}\Sigma^{\mathrm{+}}(\Omega =0^{}$and 1) states of ultracold $^{\mathrm{85}}$Rb$^{\mathrm{133}}$Cs molecule, starting with $^{\mathrm{85}}$Rb and $^{\mathrm{133}}$Cs atoms trapped in their \textbar F$_{\mathrm{Rb}}=$2\textgreater and \textbar F$_{\mathrm{Cs}}=$3\textgreater hyperfine states in dark SPOT MOTs. We have observed rich hyperfine structures of the $B^{\mathrm{1}}\Pi $, $c^{\mathrm{3}}\Sigma^{\mathrm{+}}$, and $b^{\mathrm{3}}\Pi $ states with $\Omega =$ 1, which were not observed in the FTS [1]. We will discuss the various hyperfine structures in comparisons with the hyperfine structures observed in PA to the 2$^{\mathrm{3}}\Pi (\Omega =$ 1), 2$^{\mathrm{1}}\Pi (\Omega =$ 1), and 3$^{\mathrm{3}}\Sigma ^{\mathrm{+}}(\Omega =$ 1) states [2]$\cdot $ [1] I. Birzniece \textit{et al}., J. Chem. Phys. \textbf{138}, 154304 (2013). [2] T. Shimasaki \textit{et al}., ChemPhysChem \textbf{17}, 3677 (2016). [Preview Abstract] 

D1.00054: Triplet ground state NaLi molecules Ariel Sommer, Timur M. Rvachov, Hyungmok Son, Juliana Park, Sepehr Ebadi, Martin W. Zwierlein, Wolfgang Ketterle, Alan O. Jamison The ability to produce ultracold gases of heteronuclear molecules in welldefined internal states has opened a wide range of opportunities in the study of chemical reactions, manybody physics, and quantum information science. The lightest bialkali, NaLi, offers unique advantages in the study of ultracold chemistry due to its predicted long collisional lifetime in the triplet ground state, allowing magnetic trapping and the possibility of resolved scattering resonances. We have observed the triplet ground state through twophoton spectroscopy. We report on progress toward larger molecular samples via STIRAP from loosely bound molecules, for which we are investigating approaches based on Feshbach association and multistage photoassociation. [Preview Abstract] 

D1.00055: Toward Nondestructive SingleMolecule Spectroscopy via Photon Recoil Readout Mark Kokish, Vincent Carrat, Brian Odom Spectroscopy of rovibrational transitions in molecules can uniquely provide tighter constraints on the time variation of the protontoelectron mass ratio. However, ultrahigh precision spectroscopy requires control over each molecular degree of freedom. Here we present our progress toward developing a complete blueprint for manipulating the external and internal motion of a single aluminum monohydride cation (AlH$^+$). We have previously exploited the molecule's small vibrational branching ratios to achieve rovibrational ground state preparation via optical pumping. This property can be used again to perform nondestructive state readout. After preparing AlH$^+$ and a cotrapped Ba$^+$ ion in the ion trap's motional ground state via optical pumping, the Ba$^+$ acts as a sensitive detector to molecular motion. Such motion can be induced via repeated molecular photon recoil events, contingent upon absorption out of the molecule's ground vibrational state. This photon recoil readout conveniently makes possible nondestructive rovibrational spectroscopy to a metastable vibrational excited state. The initial conditions can then quickly be regenerated using optical methods. [Preview Abstract] 

D1.00056: A Geometric Representation of Correlations: Unveiling Hidden Correlation Structures in Ultracold Matter Kenneth Wang, Anthony Mirasola, Ian White, Rick Mukherjee, Kaden Hazzard We develop a general method to visualize spin correlations and demonstrate its usefulness for ultracold systems, from fermions in lattices to trapped ions and ultracold molecules. We provide a onetoone map between the spin correlations and certain threedimensional objects, analogous to the map between single spins and Bloch vectors. Moreover, much as one can reason geometrically about dynamics using a Bloch vector  e.g. a magnetic field causes it to precess and dephasing causes it to shrink  we show that analogous reasoning holds for our visualization of correlations for real physical spin models. Phenomena that look complicated and mysterious when analyzed by the components of their correlations become simple and intuitive when described geometrically. Finally, we will describe how this geometric representation not only reveals a surprising similarity of behaviors in a wide range of spin models, but also provides insight into the accuracy of various approximations to the dynamics. [Preview Abstract] 

D1.00057: Simple model for molecular scattering Nirav Mehta, Christopher Ticknor, Kaden Hazzard The collisions of ultracold molecules are qualitatively different from the collisions of ultracold atoms due to the high density of bimolecular resonances near the collision energy. We present results from a simple $N$channel scattering model with squarewell channel potentials and constant channel couplings (inside the well) designed to reproduce essential features of chaotic molecular scattering. The potential depths and channel splittings are tuned to reproduce the appropriate density of states for the shortrange bimolecular collision complex (BCC), which affords a direct comparison of the resulting levelspacing distribution to that expected from random matrix theory (RMT), namely the socalled Wigner surmise. The density of states also sets the scale for the rate of dissociation from the BCC to free molecules, as approximated by transition state theory (TST). Our model affords a semianalytic solution for the scattering amplitude in the open channel, and a determinantal equation for the eigenenergies of the shortranged BCC. It is likely the simplest finiteranged scattering model that can be compared to expectations from the approximations of RMT, and TST. The validity of these approximations has implications for the manychannel Hubbard model recently developed [Preview Abstract] 

D1.00058: Stability of a frequencycombbased transferlock using a passive FabryPerot resonator and its application to spectroscopy of ultracold molecules Sambit Bikas Pal, Mark Lam, Kai Dieckmann In this poster, we demonstrate a transferlock laser frequency stabilization\footnote{S. B. Pal, M. M. Lam, and K. Dieckmann, Optics Letters, {\bf{41}}, 23, 55275530 (2016)} that utilizes a frequency comb (FC) and a radio frequency counter referenced to a GPS frequency standard to compensate for the frequency drifts of two lasers, which are locked to a single passive Fabry–Perot resonator (FPR). The method requires only one optical phase lock with the FC and allows transfer locking of lasers at wavelengths beyond the usable range of the FC. To attain a large frequency tuning range for the lasers, we implement optical serrodyning. We further demonstrate an efficient scheme to suppress residual amplitude modulation, thereby improving the stability of the PoundDreverHall lock used in this case. The absolute frequency stability was found to be better than $2\times10^{13}$ on timescales up to $300\,$s. Hence, together with the frequency stability on short timescales provided by the FPR, this scheme facilitates coherent Raman spectroscopy as needed for an example for the production of ultracold dipolar heteronuclear molecules. [Preview Abstract] 

D1.00059: Coherent microwave control of ultracold $^{\mathrm{23}}$Na$^{\mathrm{40}}$K molecules Zoe Yan, Yiqi Ni, Jee Woo Park, Sebastian Will, Huanqian Loh, Kang Kuen Ni, Martin Zwierlein Ultracold dipolar molecules provide new opportunities to investigate stronglycorrelated systems and quantum information science. Previously, we have demonstrated the creation of a spinpolarized ensemble of fermionic $^{\mathrm{23}}$Na$^{\mathrm{40}}$K molecules in their rovibronic and hyperfine ground state. One way to induce strong dipole moments is microwave dressing, which has also been proposed to allow shielding of inelastic collisions and the realization of topological superfluids. In contrast to static electric fields, microwave dressing allows for precise control over the orientation and strength of the molecular dipoles. We present recent work on microwave dressing of these molecules on the lowest rotational transition. The dressing induces an oscillatory dipole moment on the order of one Debye, which can prove useful in engineering interesting moleculemolecule interaction potentials. Further, we study the dependence of the molecule collision rate on the microwaveinduced dipole moment, which may have implications on the microwave trapping of molecules. [Preview Abstract] 

D1.00060: VORTICES AND EXCITATIONS IN DEGENERATE QUANTUM GASES 

D1.00061: Bent dark soliton dynamics in two spatial dimensions beyond the mean field approximation Simeon Mistakidis, Garyfallia Katsimiga, Georgios Koutentakis, Panagiotis Kevrekidis, Peter Schmelcher The dynamics of a bented dark soliton embedded in two spatial dimensions beyond the meanfield approximation is explored. We examine the case of a single bented dark soliton comparing the meanfield approximation to a correlated approach that involves multiple orbitals. Fragmentation is generally present and significantly affects the dynamics, especially in the case of stronger interparticle interactions and in that of lower atom numbers. It is shown that the presence of fragmentation allows for the appearance of solitonic and vortex structures in the higherorbital dynamics. In particular, a variety of excitations including dark solitons in multiple orbitals and vortexantidark complexes is observed to arise spontaneously within the beyond meanfield dynamics. [Preview Abstract] 

D1.00062: Quasiparticle and phaseslip induced excitations in ultracold lithium gases Francesco Scazza, Giacomo Valtolina, Pietro Massignan, Alessio Recati, Andrea Amico, Alessia Burchianti, Chiara Fort, Massimo Inguscio, Matteo Zaccanti, Giacomo Roati The fine control over interactions in ultracold Fermi gases close to a Feshbach resonance, in combination with tailored optical potentials, provide unique opportunities to explore stronglycorrelated fermion phenomena. In our ultracold lithium setup, by superimposing a thin optical barrier to a fermionic superfluid, we realize an atomic Josephson junction, where we recently studied the emergence of dissipation across the BECBCS crossover. We directly identify the main source of dissipation with the leakage into the bulk of phaseslipinduced vortex excitations nucleated within the barrier region. In another recent study, we employed radiofrequency spectroscopy to investigate highly polarized spinmixtures on the repulsive side of the Feshbach resonance. We report on the observation of welldefined repulsive quasiparticles up to unitaritylimited interactions. We characterize the essential properties of repulsive Fermi polarons: their energy, effective mass, quasiparticle residue and lifetime. [Preview Abstract] 

D1.00063: Dark soliton rings in a BoseEinstein condensate using Raman imprinting techniques Maitreyi Jayaseelan, Joseph D. Murphree, Justin T. Schultz, Azure Hansen, Nicholas P. Bigelow Soliton rings in optical beams have been theoretically and experimentally investigated for their interesting dynamics and connections with novel phenomena, including the formation of nontrivial topological states such as vortices. Density and phase engineering techniques have been proposed to create soliton rings in BoseEinstein condensates. Here, we explore using a coherent twophoton Raman optical imprinting technique to generate dark soliton rings in a Zeeman spin state of a $^{87}$Rb BoseEinstein condensate (BEC). The relative intensities and phase of the Raman beams determine the relative populations and phase of the atomic spin states, which can then be measured through atomoptic polarimetry. Dark soliton rings correspond to an annular edge dislocation with a phase jump of $\pi$, forcing the density to vanish at the dislocation. We use higherorder LaguerreGauss $\textit{p}$modes with the requisite singular phase and intensity profiles to create concentric soliton rings in the BEC via the Raman process, creating dark soliton rings in one spin component filled with population from the second component. Resonant depletion allows us to selectively remove one spin state, facilitating evolution studies of both filled and dark soliton rings. [Preview Abstract] 

D1.00064: Collective modes of a soliton train in a Fermi superfluid Shovan Dutta, Erich Mueller We characterize the collective modes of a soliton train in a quasionedimensional Fermi superfluid, using a meanfield formalism. In addition to the expected Goldstone and Higgs modes, we find novel longlived gapped modes associated with oscillations of the soliton cores. The soliton train has an instability that depends strongly on the interaction strength and the spacing of solitons. It can be stabilized by filling each soliton with an unpaired fermion, thus forming a commensurate FuldeFerrellLarkinOvchinnikov phase. We find such a state is always dynamically stable, which paves the way for realizing them in experiments via phase imprinting. [Preview Abstract] 

D1.00065: Decay of Josephson Superflow via VortexRing Emission Nick Proukakis, Klejdja Xhani, Kean Loon Lee, Luca Galantucci, Andrea Trombettoni, Giacomo Valtolina, Francesco Scazza, Andrea Amico, Chiara Fort, Matteo Zaccanti, Alessia Burchianti, Giacomo Roati Josephson oscillations in fermionic superfluids across the BECBCS crossover (Valtolina et al., Science 350, 15050 (2015)) have been recently experimentally observed to decay through the emission of vortical excitations at the barrier connecting the two parts of the superfluid in a doublewell trap. By performing full 3D numerical simulations in the molecular BEC regime at both zero and finite temperatures, we explicitly demonstrate the generated structures to be excited vortex rings, and study their propagation, dynamical instability and subsequent decay, shedding more light into this nonlinear process, the role of interactions of vortex rings with other rings and background sound, and the effect of gradually removing the barrier (experimental step undertaken before timeofflight imaging). By selfconsistently coupling the GrossPitaevskii equation to a quantum Boltzmann equation (“ZNG” model) we also discuss the role of finite temperature in damping both Josephson oscillations and macroscopic quantum selftrapping. [Preview Abstract] 

D1.00066: QUANTUM INFORMATION 

D1.00067: Comparing Zeeman qubits to hyperfine qubits in the context of the surface code: $^{171}$Yb$^{+}$ and $^{174}$Yb$^{+}$ N.C. Brown, K.R. Brown Many systems used for quantum computing possess additional states beyond those defining the qubit. Leakage out of the qubit subspace must be considered when designing quantum error correction codes (QECC). Here we consider trapped ion qubits manipulated by Raman transitions. Zeeman qubits do not suffer from leakage errors but are sensitive to magnetic fields to firstorder. Hyperfine qubits can be chosen to be insensitive to magnetic fields to firstorder, clock states, but spontaneous scattering during the Raman transition can lead to leakage. Here we compare a Zeeman qubit ($^{174}$Yb$^+$) to a hyperfine qubit ($^{171}$Yb$^+$) in the context of the surface code. We find that the number of physical qubits required to reach a specific logical qubit error can be reduced by using $^{174}$Yb$^+$ if the magnetic field can be stabilized to $10^{5}G$. [Preview Abstract] 

D1.00068: MultiValued Logic, Neutrosophy, and Schr\"{o}dinger Equation Florentin Smarandache, Victor Christianto Discussing some paradoxes in Quantum Mechanics from the viewpoint of MultiValuedlogic pioneered by Lukasiewicz, and the recent concept Neutrosophic Logic. Essentially, this new concept offers new insights on the idea of `identity', which too often it has been accepted as given. Neutrosophy itself was developed in attempt to generalize FuzzyLogic introduced by L. Zadeh. The discussion is motivated by observation that despite almost eight decades, there is indication that some of those paradoxes known in Quantum Physics are not yet solved. In our knowledge, this is because the solution of those paradoxes requires reexamination of the foundations of logic itself, in particular on the notion of identity and multivaluedness of entity. The discussion is also intended for young physicist fellows who think that somewhere there should be a `complete' explanation of these paradoxes in Quantum Mechanics. If this it doesn't answer all of their questions, it is our hope that at least it offers a new alternative viewpoint for these old questions. [Preview Abstract] 

D1.00069: Microfabricated MicrowaveIntegrated Surface Ion Trap Melissa C. Revelle, Matthew G. Blain, Raymond A. Haltli, Andrew E. Hollowell, Christopher D. Nordquist, Peter Maunz Quantum information processing holds the key to solving computational problems that are intractable with classical computers. Trapped ions are a physical realization of a quantum information system in which qubits are encoded in hyperfine energy states. Coupling the qubit states to ion motion, as needed for twoqubit gates, is typically accomplished using Raman laser beams. Alternatively, this coupling can be achieved with strong microwave gradient fields\footnote{U. Warring \textit{et al.,} PRL \textbf{110}, 173002 (2013); T. P. Harty \textit{et al.,} PRL \textbf{117}, 140501 (2016).}. While microwave radiation is easier to control than a laser, it is challenging to precisely engineer the radiated microwave field. Taking advantage of Sandia's microfabrication techniques, we created a surface ion trap with integrated microwave electrodes with subwavelength dimensions. This multilayered device permits colocation of the microwave antennae and the ion trap electrodes to create localized microwave gradient fields and necessary trapping fields. Here, we characterize the trap design and present simulated microwave performance with progress towards experimental results. [Preview Abstract] 

D1.00070: The generalized analytical model and DSMC simulations of highspeed rotating flow in polar $(r  \theta ) $coordinate Dr. Sahadev Pradhan The generalized analytical model for the radial boundary layer in a highspeed rotating cylinder is formulated for studying the gas flow field due to insertion of mass, momentum and energy into the rotating cylinder in the polar~ $(r  \theta )$~plane. The analytical solution includes the sixth order differential equation for the radial boundary layer at the cylindrical curved surface in terms of master potential~($\chi )$, which is derived from the equations of motion in a polar~$(r  \theta )$~plane. The linearization approximation ((Pradhan {\&} Kumaran\textit{, J. Fluid Mech }); (Kumaran {\&} Pradhan, \textit{J. Fluid Mech })) is used, where the equations of motion are truncated at linear order in the velocity and pressure disturbances to the base flow, which is a solidbody rotation. Additional assumptions in the analytical model include constant temperature in the base state (isothermal condition), and high Reynolds number, but there is no limitation on the stratification parameter. The analytical solutions are compared with direct simulation Monte Carlo (DSMC) simulations and found good agreement (with a difference of less than 10{\%}), provided the boundary conditions are accurately incorporated in the analytical solution. The slow down of the circumferential velocity of the bulk of the rotating fluid due to the presence of stationary intake tube is studied for stratification parameter in the range 0.707$$3.535, and found significant slow down (between 8 to 28{\%}), which induces the secondary radial flow towards the axis, and it further excites the secondary axial flow, which could be very important for the centrifugal gas separation processes. [Preview Abstract] 

D1.00071: Grover's unstructured search by using a transverse field Zhang Jiang, Eleanor Rieffel, Zhihui Wang We design a circuitbased quantum algorithm to search for a needle in a haystack, giving the same quadratic speedup achieved by Grover's original algorithm. In our circuitbased algorithm, the problem Hamiltonian (oracle) and a transverse field (instead of Grover's diffusion operator) are applied to the system alternatively. We construct a periodic time sequence such that the resultant unitary drives a closed transition between two states, which have high degrees of overlap with the initial state (even superposition of all states) and the target state, respectively. Let $N = 2^n$ be the size of the search space. The transition rate in our algorithm is of order $\Theta(1/\sqrt N)$, and the overlaps are of order $\Theta(1)$, yielding a nearly optimal query complexity of $T\simeq \sqrt N (\pi/2\sqrt 2\,)$. Our algorithm is inspired by a class of algorithms proposed by Farhi et al. [arXiv:1411.4028], namely the Quantum Approximate Optimization Algorithm (QAOA); our method offers a route to optimizing the parameters in QAOA by restricting them to be periodic in time. [Preview Abstract] 

D1.00072: Theoretical study of the adsorption energy of some linear saturated hydrocarbons on SWCNT: DFT calculations Hewa Abdullah, Hassan H. Abdallah Carbon nanotubes represent one of the building blocks of innovation across most industries. Carbon nanotubes have many applications based on the aspect ratio, mechanical strength, electrical and thermal conductivity of these nano materials. In this study the adsorption of a single molecule of the some linear saturated hydrocarbons inside and on the surface of a tube of singlewalled carbon nanotubes (SWCNT) was investigated using Density Function Theory (DFT). The results showed that all guest molecules prefer to be adsorbed into the surface of SWCNT rather than into the CNT tube. Upon adsorption of the guest molecules, the energy gap was considerably reduced, resulting in improved electrical conductivity. DOS and NBO analysis were performed to discover intermolecular interactions. Chemical reactivity was investigated in terms of chemical hardness, softness and absolute electronegativity [Preview Abstract] 

D1.00073: Hiddenvariable hypothesis in quantum paradoxes Florentin Smarandache, Victor Christianto It would be incomplete to discuss quantum paradoxes, in particular Schr\"{o}dinger's cat paradox, without mentioning hiddenvariable hypothesis. There are various versions of this argument, but it could be summarised as an assertion that there is `something else' which should be included in the Quantum Mechanical equations in order to explain thoroughly all quantum phenomena. Sometimes this assertion can be formulated in question form: ``Can quantum mechanics be considered complete?'' Interestingly, however, the meaning of `complete' itself remains quite abstract (fuzzy). An interpretation of this cat paradox suggests that the problem arises because we mix up the macroscopic systems (observer's wavefunction and apparatus' wavefunction) from microscopic system to be observed. In order to clarify this, it is proposed that the measurement apparatus should be described by a classical model, and the physical system by a quantum model. [Preview Abstract] 

D1.00074: Synthesizing complex spin networks with spinmotion coupled neutral atoms in photonic crystals Ying Dong We develop a toolbox for realizing ``fully programmable'' ddimensional pairwise interacting lattice spin systems with spinmotion coupled neutral atoms in the vicinity of 1D photonic crystal waveguides. The enabling platform thereby allows to synthesize a wide range of strongly interacting quantum materials by way of vacuumengineered interatomic kinetic interactions. We demonstrate the versatility of our assembly language approach towards arbitrary SU(2)lattice spin models with explicit constructions of familiar Hamiltonians for perfect state transfer in 1D spin chains, lattice gauge theories, and topologicallyquantum spin liquids. We further construct DzyaloshinskiMoriya interaction for the realization ofspin liquids and longrange random quantum magnets with spinglass phase. [Preview Abstract] 

D1.00075: Applications of the trilinear Hamiltonian with three trapped ions Roland Esteban Hablutzel Marrero, Shiqian Ding, Gleb Maslennikov, Jaren Gan, Stefan Nimmrichter, Alexandre Roulet, Jibo Dai, Valerio Scarani, Dzmitry Matsukevich The trilinear Hamiltonian $a^{\dagger}bc + ab^{\dagger}c^{\dagger}$, which describes a nonlinear interaction between harmonic oscillators, can be implemented to study different phenomena ranging from simple quantum models to quantum thermodynamics. We engineer this coupling between three modes of motion of three trapped $^{171}\mathrm{Yb}^+$ ions, where the interaction arises naturally from their mutual (anharmonic) Coulomb repulsion. By tuning our trapping parameters we are able to turn on / off resonant exchange of energy between the modes on demand. We present applications of this Hamiltonian for simulations of the parametric down conversion process in the regime of depleted pump, a simple model of Hawking radiation, and the TavisCummings model. We also discuss the implementation of the quantum absorption refrigerator in such system and experimentally study effects of quantum coherence on its performance. [Preview Abstract] 

D1.00076: Towards quantum manybody physics with Sr in optical lattices Stepan Snigirev, André Heinz, Annie Jihyun Park, Stephan Wissenberg, Jean Dalibard, Immanuel Bloch, Sebastian Blatt The widespread use of ultracold fermionic strontium atoms in optical lattices for precision measurements has led to the availability of many advanced tools and techniques for these atoms. With the recent realization of degenerate gases of all Sr isotopes and the development of fermionic quantum gas microscopes for alkali atoms, a new frontier has opened for quantum simulations and quantum information processing with fermionic $^{87}Sr$. Many applications in quantum state engineering and quantum simulation require internalstatedependent control of the atomic motion. In the Sr atom, there exist socalled tuneout wavelengths, where only one of the clock states is trapped and the other state can move freely. Because of the (in principle) exact cancellation of the other state’s polarizability at the tuneout wavelengths, it should be possible to realize spindependent lattices with high fidelity. Here, we propose a system to realize such internalstatedependent control of the atomic motion and report on the construction of a new experiment towards quantum simulations with Sr in optical lattices. [Preview Abstract] 

D1.00077: Adiabatic ground state preparation in an expanding lattice Snir Gazit, Chris Olund, Norman Yao We numerically investigate the newly proposed ssource framework for constructing ground state wave functions of gapped Hamiltonians. The key idea is to utilize the adiabatic principle to build a tensor network representation that smoothly interpolates between the ground state of system sizes L and 2L via an interleaved set of ancillary degrees of freedom. Repeatedly applying this procedure reproduces the thermodynamic limit. The scheme should be contrasted with conventional tensor network methods that rely on the variational principle to target the ground state by iteratively improving a variational energy. We introduce a simple yet flexible tensor network structure and an optimization protocol borrowing techniques from quantum control theory. We anticipate that this approach can, in principle, allow access to problems beyond current tensor network technology and even serve as an experimental scheme for ground state preparation in quantum engineered systems. [Preview Abstract] 

D1.00078: Quantum simulations of quantum magnetism with hundreds of trapped ions Kevin Gilmore, Justin Bohnet, Elena Jordan, Martin Gaerttner, Arghavan SafaviNaini, Ana Maria Rey, John Bollinger Quantum simulators, where one wellcontrolled physical system mimics another complex system, may enable understanding of quantum manybody physics that cannot be fully studied using conventional techniques on classical computers. We describe quantum simulations of a network of interacting magnetic spins performed with 2dimensional arrays of hundreds Be$^{+}$ ions crystallized in a Penning trap. We discuss how we engineer a tunable transverse Ising model, and explain how we generate and observe farfromequilibrium quantum spin dynamics, including signatures of entanglement. We summarize progress exploring optimized adiabatic protocols for preparing low energy states of the transverse Ising Hamiltonian and implementing a subDoppler cooling scheme for the drumhead modes of the ion array. [Preview Abstract] 

D1.00079: Integrated Technologies for ChipScale TrappedIon Quantum Control Robert McConnell, Suraj Bramhavar, Colin Bruzewicz, Dave Kharas, William Loh, Karan Mehta, Jason Plant, Jonathan Sedlacek, Cheryl SoraceAgaskar, Jules Stuart, John Chiaverini, Rajeev Ram, Jeremy Sage Microfabricated iontrap arrays are attractive platforms for scalable quantum information processing with large numbers of qubits. The robust photolithographic techniques used to define the trapping electrodes can potentially be combined with integrated photonic devices and CMOS electronics to build a single system that performs the key functions of a quantum information processor onchip. Here we describe progress towards the demonstration of the components of an integrated chipscale platform, focusing on multilayer photonic waveguides to route multiple laser beams throughout a trap array, integrated photodetectors for ionstate readout, and embedded CMOS circuitry for onchip electronic control. [Preview Abstract] 

D1.00080: Fast scrambling in the SachdevYeKitaev model: a numerical test Christopher Olund, Norman Yao, Joel Moore Understanding the approach toward thermalization in isolated quantum systems is challenging. This approach is thought to be characterized by the delocalization, or scrambling, of quantum information over all of a system’s degrees of freedom. Recently, connections have been made between black holes, conjectured to be the fastest scramblers in nature, and model spin and fermionic hamiltonians. These models typically live on fully connected graphs, naturally motivating the question: are alltoall interactions necessary for fast scrambling? Here, we numerically probe the scrambling rate of the SachdevYeKitaev model for intermediate system sizes and vary the range of the underlying interactions. By fitting out of time ordered correlation functions to a known analytic expression, we extract the scrambling rate and perform a detailed finite size scaling analysis. Extrapolating to the thermodynamic limit, we find reasonable agreement with a recently conjectured bound for low to intermediate temperatures. [Preview Abstract] 

D1.00081: Quantum simulation of spinbath dynamics with trapped ions Dylan Gorman, Eli Megidish, Borge Hemmerling, Hartmut Haeffner Chains of trapped ions are an ideal platform for studying the dynamics of qubits coupled to bosonic environments. This kind of dynamics is of interest in many current problems in physics and biology such as charge transport, photosynthesis, and olfaction. In a chain of N trapped ions, an experimenter has access to an environment of the 3N vibrational modes of the chain, allowing for the simulation of very large vibrational environments with tunable spectral properties. In addition, the ions also serve as qubits, and both qubitqubit and qubitbath interactions can be engineered via quantum gates. Here, we discuss recent experimental progress investigating spinbath dynamics in ion strings. We explore what happens as the spinbath coupling is varied, as well as when the thermal occupation and quantum state of the environment is varied. [Preview Abstract] 

D1.00082: Sorting atoms in a 3D optical lattice Aishwarya Kumar, TsungYao Wu, Yang Wang, David Weiss ~We report on an atom sorting scheme for perfect pattern formation in a 3D 5x5x5 optical lattice of Cesium atoms, originally~proposed in Phys. Rev. A 70, 040302(R) (2004). The combination of site selective state flips and with state selective motion steps can quickly and reliably fill site vacancies. We have previously demonstrated high fidelity site selective single qubit gates in this lattice which can be adapted to be the state flips in this scheme [Science 352, 15621565 (2016)]. Our newer work demonstrates high fidelity state selective atomic motion. [Preview Abstract] 

D1.00083: Trapped ion system for sympathetic cooling and nonequilibrium dynamics Charlie Doret, Sierra Jubin, Sarah Stevenson Atomic systems are superbly suited to the study of nonequilibrium dynamics. These systems’ exquisite isolation from environmental perturbations leads to long relaxation times that enable exploration of farfromequilibrium phenomena. We present progress towards trapping chains of multiple cotrapped calcium isotopes geared towards measuring thermal equilibration and sympathetic cooling rates. We also discuss plans for future experiments in nonequilibrium statistical mechanics, including exploration of the quantumtoclassical crossover between ballistic transport and diffusive, Fourier’s Law conduction. [Preview Abstract] 

D1.00084: ATOM AND MATTER OPTICS 

D1.00085: MagneticGradient ColdAtom Launching Benedict Feinberg, Harvey Gould, Rapha\"{e}l Jannin, Charles T. Munger Jr., Hiroshi Nishimura We have extended our simulations (http://meetings.aps.org/Meeting/APR17/Session/F1.39) of beam transport of ultra cold (2 $\mu$K) and cold (130 $\mu$K) neutral Cs atoms. In addition to falling under gravity, focusing, and reversing direction, ultra cold atoms in our simulations are now longitudinally bunched and accelerated, reaching 0.5 m above their starting point. An experimental apparatus to test the simulations is being constructed. Experimental progress will be described. [Preview Abstract] 

D1.00086: Atomic Coherence Effects of Scattered Light in a $\Lambda $Type Atomic System of D$_{\mathrm{1}}$line of $^{\mathrm{85}}$Rb Atoms Seong Ho Min, Han Seb Moon We report the twophoton coherence effects by scattered light in D$_{\mathrm{1}}$line of $^{\mathrm{85}}$Rb atoms, such as electromagnetically induced transparency (EIT), electromagnetically induced absorption (EIA), and electromagnetically induced focusing (EIF), in a paraffincoated Rb vapor cell. Especially, according to the direction of the scattered light, subnatural width EIAlike and EIT spectra of the scattered light were measured simultaneously. We will illuminate the interesting spectra of the scattered light as twophoton coherence effects. [Preview Abstract] 

D1.00087: Correlated PhotonPair Generation Based on Spontaneous FourWave Mixing in Open {\&} Closed LadderType Atomic System Jiho Park, Han Seb Moon We obtained a bright photonpair source via spontaneous fourwave mixing in a Dopplerbroadened atomic ensemble of the open (5D$_{\mathrm{1/2}}$  5P$_{\mathrm{3/2}}$  5D$_{\mathrm{5/2}})$ and closed (5D$_{\mathrm{1/2}}$  5P$_{\mathrm{3/2}}$  5D$_{\mathrm{3/2}})^{\mathrm{\thinspace }}$laddertype atomic systems of $^{\mathrm{87}}$Rb. We characterize and compare the photonpairs generated from both atomic configurations according to the vapor cell temperature and the pump and coupling powers. The coincidence counting rate of the open atomic system is smaller than that of the closed system under the same conditions because of different twophoton coherence. Our bright photon pair source will be used for two photon interference and quantum memory experiment. We believe that our source is important as a useful quantum light source. [Preview Abstract] 

D1.00088: PhotonPair Generation in Cold Atomic Ensemble for LongDistance Quantum Communication Pyeong woo Kim, Han Seb Moon One of the common methods for overcoming limitation of longdistance quantum communication is using entangled photon pair sources between 1.5$\mu $m band photon and near infrared photon. We investigate the threephoton electromagnetically induced absorption (TPEIA) and fourwave mixing (FWM) in the 5S$_{\mathrm{1/2}}$5P$_{\mathrm{3/2}}$4D$_{\mathrm{5/2}}$ transition of $^{\mathrm{87}}$Rb atoms. We will report the photonpairs with 780nm and 1.5$\mu $m generated by spontaneous fourwave mixing in this transition of $^{\mathrm{87}}$Rb. [Preview Abstract] 

D1.00089: Storage of Heralded Single Photons in Warm Atomic Ensemble. Taek Jeong, Han Seb Moon We report the correlated photonpair generation and the storage of heralded single photons in a warm atomic ensemble. We observed the correlated photonpairs from warm atomic ensemble of $^{\mathrm{87}}$Rb by using spatially prepared optical pumping process. The process is realized by donutlike optical pumping beam. The photon pairs are generated at the dark region, which is the center of the optical pumping beam, for reducing fluorescent noise. And we performed experiment for storage of heralded single photons by using another warm $^{\mathrm{87}}$Rb atom via electromagnetically induced transparency (EIT). We will illuminate single photon manipulation process based on warm atomic ensembles. [Preview Abstract] 

D1.00090: Single Atoms in Nearly Concentric Cavity Adrian Nugraha Utama, Chi Huan Nguyen, Nick Lewty, Christian Kurtsiefer Strong interaction between photons and neutral single atoms are usually observed in cavity quantum electrodynamics (CQED) systems with high finesse mirrors and small physical volume. We demonstrate another approach that employs a near concentric cavity with relatively low finesse mirrors ($\sim$ 100) and large physical separation between mirrors ($\sim$ 10 mm). The transmission spectrum of our CQED system with trapped single atoms is observed to exhibit two resolved normal mode peaks, in which the single atom cooperativity is estimated to be around 0.4. The cooperativity of the system can be improved further by increasing the finesse of the mirrors or moving the cavity closer to the concentric point. The successful realization of concentric CQED systems will open opportunities for scaling up with applications in quantum computing. [Preview Abstract] 

D1.00091: Compact Surface Plasmon Resonance Biosensor for Fieldwork Environmental Detection Margrethe Boyd, Madison Drake, Kristian Stipe, Monica Serban, Ivana Turner, Aaron Thomas, David Macaluso The ability to accurately and reliably detect biomolecular targets is important in innumerable applications, including the identification of foodborne parasites, viral pathogens in human tissue, and environmental pollutants. While detection methods do exist, they are typically slow, expensive, and restricted to laboratory use. The method of surface plasmon resonance based biosensing offers a unique opportunity to characterize molecular targets while avoiding these constraints. By incorporating a plasmonsupporting gold film within a prism/laser optical system, it is possible to reliably detect and quantify the presence of specific biomolecules of interest in real time. This detection is accomplished by observing shifts in plasmon formation energies corresponding to optical absorption due to changes in index of refraction near the goldprism interface caused by the binding of target molecules. A compact, inexpensive, batterypowered surface plasmon resonance biosensor based on this method is being developed at the University of Montana to detect waterborne pollutants in fieldbased environmental research. [Preview Abstract] 

D1.00092: QUANTUM OPTICS 

D1.00093: Highefficiency Coherent Optical Memory based on Electromagnetically Induced Transparency. YingCheng Chen, YaFen Hsiao, PinJu Tsai, HungShiue Chen, ShengXiang Lin, ChihChiao Hung, ChihHsi Lee, YiHsin Chend, YongFan Chen, Ite Albert Yu Quantum memory is a crucial component in the longdistance quantum communication based on quantum repeaters. To outperform the direct transmission of photons with quantum repeaters, it is crucial to develop quantum memories with high fidelity, high efficiency and a long storage time. Here, we present our work to achieve a storage efficiency of larger than 90{\%} for a coherent memory based on the electromagnetically induced transparency (EIT) scheme in cold atomic media with an optical depth of \textasciitilde 1000. At a storage efficiency of 50{\%}, we also obtain a fractional delay of 1200. At high optical depths, nonlinear optical effects, such as the photon switching and fourwave mixing due to the offresonant excitation of the EIT control field, may become significant and introduce complications in quantum memory applications. We discuss and present methods to reduce these complications. [Preview Abstract] 

D1.00094: Cooperative spontaneous emissions from resonant longrange dipoledipole interactions: Super and subradiance, and superradiant laser HsiangHua Jen, MingShien Chang, YingCheng Chen Resonant longrange dipoledipole interaction (LRDDI) has played an important role in initiating super and subradiance in a cold atomic ensemble. This universal effect is induced from the atomphoton interaction in the dissipation process. Here we propose a complete space of singlyexcited states which can be the candidates for superradiance and subradiance. Cooperative single and multiphoton subradiant states can also be prepared in our proposed scheme by imprinting the required phases via pulsed gradient magnetic or electric fields. This effect of LRDDI is also present in a steadystate superradiant laser (SL) in the badcavity limit. We demonstrate that cavity photon number oscillates as an interparticle distance of the atoms varies. Similarly the atomatom coherence alternates with signs, showing critical transitions alternatively in SL operations. This suggests a complexity of the collective effect emerging in a large ensemble of atoms. The scaling of a finite number of atoms shows that a steadystate SL outperforms the one without LRDDI, which allows for probing narrow atomic transitions and is potentially useful for precision measurements and nextgeneration optical clocks. [Preview Abstract] 

D1.00095: Towards quantum memory with rareearthions in crystals Haoquan Fan, Elizabeth A. Goldschmidt Quantum memory is essential to the future of quantum information. At cryogenic temperatures, solids containing rareearthions (REI) offer naturally trapped atomic systems for quantum memory implementations. The properties of REI in crystals enable broadband, efficient, and longlived quantum memory in solid state materials. Progress todate toward ensemblebased quantum memory with REI solids has been hampered by inhomogeneous broadening. Recent progress on stoichiometric materials narrows down the inhomogeneous broadening by 2 orders of magnitude, opening up new avenues for quantum memory. We report progress toward quantum memory with $\mathrm{Eu^{3+}}$ in crystals. [Preview Abstract] 

D1.00096: Line shapes in Vtype electromagnetically induced transparency for 87Rb atoms: theory and experiment HyunJong Kang, HeungRyoul Noh We present a theoretical and experimental study of electromagnetically induced transparency (EIT) in Vtype systems of $^{\mathrm{87}}$Rb atoms. The probe beam frequency is locked to the F$_{\mathrm{g}}=$2$\to $F$_{\mathrm{e}}=$2 and F$_{\mathrm{g}}=$2$\to $F$_{\mathrm{e}}=$1 transitions of D$_{\mathrm{1}}$ line and the coupling beam frequency is scanned around the F$_{\mathrm{g}}=$2$\to $F$_{\mathrm{e}}=$1,2,3 transitions of D$_{\mathrm{2}}$ line. The polarizations of the probe and coupling beams are linear in parallel or perpendicular direction. We calculate accurate line shapes of Vtype EIT spectra using density matrix equations by considering all the magnetic sublevels and compare them with experimental results. To discriminate the contribution of coherence term, we perform similar calculations by ignoring the coherences between the sublevels in the 5P$_{\mathrm{1/2}}$ state and those in the 5P$_{\mathrm{3/2}}$ state. We find that the coherence effect is significant only for the cycling transition line. [Preview Abstract] 

D1.00097: Lightdragging effect in a moving electromagnetically induced transparent medium Chang Huang, PeiChen Kuan, ShauYu Lan As one of influential experiments on the development of modern physics, the phenomenon of light dragging in a moving medium has been discussed and observed extensively in different types of systems. In order to get a larger dragging effect, a long duration of light traveling in the medium is preferred. We therefore demonstrate a lightdragging experiment in an electromagnetically induced transparent cold atomic ensemble to enhance the dragging effect by at least three orders of magnitude compared with the previous experiments. With a large enhancement of the dragging effect, we realize an atombased velocimeter that has a sensitivity two orders of magnitude higher than the velocity width of the atomic medium used. The result suggests the possibility of making a motional sensor using the collective state of atoms in a room temperature vapor cell or solid state material in the future. [Preview Abstract] 

D1.00098: Secondorder correlation of an optomechanical oscillator Hyojun Seok, Dongyel Kang We investigate an optomechanical oscillator quadratically coupled to a singlemode cavity field in the regime in which the cavity dissipation is a dominant source of damping. The mechanical oscillator experiences effective cubic nonlinear interaction following the dynamics of the cavity field adiabatically. We show that the mechanical oscillator is coupled to an effective optical reservoir in addition to its own mechanical heat bath. It is shown that the effective optical reservoir leads to nonlinear cooling of the mechanical oscillator in the thermal limit and antibunching of the phonon field in the quantum regime. We find the condition of the transition from bunching to antibunching of the phonon field both numerically and analytically. [Preview Abstract] 

D1.00099: Visible Quantum Imaging of Infrared Ghost Felix Jaetae Seo, Quinton Rice, Dulitha Jayakodige, Tikaram Neupane, Bagher Tabibi 

D1.00100: Abstract Withdrawn 

D1.00101: Abstract Withdrawn Planck firstly put forward the ``quantum" hypothesis, however, for a long time, he always tried to modify his own theory according to classic idea of continuity and to introduce ``quantum" concept into framework of classical physics. Till today, the contradiction of ``classic and quantum", ``continuance and separation" and ``particles and waves" have plagued physics so much. Based on abstraction and generalization of the three contradictions, especially the strong demand to resolve classical electromagnetic field into elementwaves of photons, a mathematical conjecture was offered by Yongchao Gan that any positive real number R must equal to the algebraic sum of integer multiple of a series of different positive real number ri. Several years later, this conjecture was proved according to rigorous mathematic methodology by changing a complex algebraic problem into a single geometrical one, which radically solved the contradiction of ``classic and quantum", ``separation and continuance" and ``particles and waves". 

D1.00102: Transfer of Orbital and Spin angular momentum from nonparaxial optical vortex to atomic BEC Anal Bhowmik, Pradip Kumar Mondal, Sonjoy Majumder, Bimalendu Deb Allen and coworkers first brought up the realization that optical vortex can carry well defined orbital angular momentum (OAM) associated with its spatial mode. Spin angular momentum (SAM) of the light, associated with the polarization, interacts with the internal electronic motion of the atom. The exchange of orbital angular momentum (OAM) between optical vortex and the centerofmass (CM) motion of an atom or molecule is well known in paraxial approximation. We show that, how the total angular momentum (TAM) of nonparaxial optical vortex is shared with atom, in terms of OAM and SAM. Both the angular momenta are now possible to be transferred to the internal electronic and external CM motion of atom. Here we have studied how the Rabi frequencies of the excitations of twophoton Raman transitions with respect to focusing angles. Also, we investigate the properties of the vortex superposed state for a BoseEinstein condensate condensate by a single nonparaxial vortex beam. The density distribution of the vortexantivortex superposed state has a petal structure which is determined by the quantum circulations and proportion of the vortex and antivortex. [Preview Abstract] 

D1.00103: EIT amplitude noise spectroscopy Benjamin Whitenack, Devan Tormey, Shannon O'Leary, Michael Crescimanno EIT Noise spectroscopy is usually studied by computing a correlation statistic based on temporal intensity variations of the two (circular polarization) propagation eigenstates. Studying the intensity noise correlations that result from amplitude mixing that we perform before and after the cell allows us to recast it in terms of the underlying amplitude noise. This leads to new tests of the quantum optics theory model and suggests an approach to the use of noise spectroscopy for vector magnetometry. [Preview Abstract] 

D1.00104: Longlived quantum coherences in symmetric Vsystem strongly driven by incoherent light Suyesh Koyu, Timur Tscherbul The threelevel Vsystem is a prototype model of quantum coherent dynamics in multilevel systems, including photosynthetic lightharvesting complexes and photovoltaic devices. The symmetric Vsystem weakly irradiated by incoherent light undergoes coherent dynamics under certain conditions [1]. Here, we explore the coherent dynamics in the limit where incoherent driving is fast compared to the radiative decay rates. The twophoton quantum coherences between the excited levels of the symmetric Vsystem display an oscillatory behavior in the underdamped regime ($\Delta/\gamma > \bar{n}$) and reach a longlived quasistationary state in the overdamped regime ($\Delta/\gamma < \bar{n}$) for the effective photon occupation numbers $\bar{n}\gg 1$. The lifetime of the longlived coherent state scales as $\bar{n}(\Delta/\gamma)^{2}$ for $p>p_c$, where $p_c$ is a critical value of the transition dipole alignment factor ($p_c= 1\varepsilon$ with $\varepsilon \to 0$ over a wide range of excitedlevel splittings $\Delta$ and radiative decay rates $\gamma$). For $p 

D1.00105: Singlephoton nonlinearities in the propagation of focused beams through dense atomic clouds Yidan Wang, Alexey Gorshkov, Michael Gullans We theoretically study singlephoton nonlinearities realized when a highly focused Gaussian beam passes through a dense atomic cloud. In this system, strong dipoledipole interactions arise between closely spaced atoms and significantly affect light propagation. We find that the highly focused Gaussian beam can be treated as an effective onedimensional waveguide, which simplifies the calculation of photon transmission and correlation functions. The formalism we develop is also applicable to the case where additional atomatom interactions, such as interactions between Rydberg atoms, are involved. [Preview Abstract] 

D1.00106: Optical Control of a Nuclear Spin in Diamond David Levonian, Michael Goldman, Kristiaan DeGreve, Soonwon Choi, Matthew Markham, Daniel Twitchen, Mikhail Lukin The nitrogenvacancy (NV) center in diamond has emerged as a promising candidate for quantum information and quantum communication applications. The NV center's potential as a quantum register is due to the long coherence time of its spintriplet electronic ground state, the optical addressability of its electronic transitions, and the presence of nearby ancillary nuclear spins. The NV center's electronic spin and nearby nuclear spins are most commonly manipulated using applied microwave and RF fields, but this approach would be difficult to scale up for use with an array of NVbased quantum registers. In this context, alloptical manipulation would be more scalable, technically simpler, and potentially faster. Although alloptical control of the electronic spin has been demonstrated, it is an outstanding problem for the nuclear spins. Here, we use an optical Raman scheme to implement nuclear spinspecific control of the electronic spin and coherent control of the $^{\mathrm{14}}$N nuclear spin. [Preview Abstract] 

D1.00107: Engineering strong nonlocal interactions in a nearconcentric cavity Emily Davis, Gregory Bentsen, Tracy Li, Monika SchleierSmith Photonmediated interactions among atoms coupled to an optical cavity are a powerful tool for engineering quantum manybody Hamiltonians. We present an experiment aimed at generating nonlocal and dynamically controllable spinspin interactions by strongly coupling 87Rb atoms to a nearconcentric cavity. The tightlyfocused waist of 11um combined with a high finesse of 60,000 yields a singleatom cooperativity of 50. Furthermore, the optical access afforded by the nearconcentric geometry enables imaging and addressing with 1um resolution. We detail the current status of the experiment and progress toward manybody quantum control. [Preview Abstract] 

D1.00108: Engineering a Trapped Ion OpenSystem Dicke Model with Dissipative Phase Transitions Florentin Reiter, Malte D. Dueholm, Anders S. Sorensen, Susanne F. Yelin The Dicke model [1] is a paradigmatic model in quantum optics known to exhibit a quantum phase transition between a normal and a superradiant phase [2]. Such superradiant phase transitions have recently been observed experimentally using cavity systems [3,4]. These implementation have, however, conserved the total spin and thus restricted the dynamics. To overcome such restrictions, we consider implementation of an opensystem Dicke model using systems of trapped ions. Here spontaneous emission breaks the symmetry and thereby allows the system to explore richer drivendissipative dynamics. We observe phase transitions in the steady state with respect to both Hamiltonian and dissipative parameters, as well as novel phases which do not appear in closed systems and cavity realizations. [1] R. H. Dicke, Phys. Rev. 93, 99 (1954). [2] K. Hepp and E. H. Lieb, Ann. Phys. 76, 360 (1973); Y. K. Wang and F. T. Hioe, Phys. Rev. A 7, 831 (1973). [3] K. Baumann et al., Nature 464, 1301 (2010). [4] M. Baden et al., Phys. Rev. Lett. 113, 020408 (2014). [Preview Abstract] 

D1.00109: STRONGFIELD PHYSICS 

D1.00110: Unravelling the dynamical origin of below and nearthreshold harmonic generation of H$_{\mathrm{2}}^{\mathrm{+\thinspace }}$in an intense NIR laser field John Heslar, ShihI Chu Recently, the study of near and belowthreshold regime harmonics as a potential source of intense coherent vacuumultraviolet radiation has received considerable attention. However, the dynamical origin of these lower harmonics, particularly for the molecular systems, is less understood and largely unexplored. Here we present a fully ab initio and high precision 3D quantum study of the below and nearthreshold harmonic generation of H$_{\mathrm{2}}^{\mathrm{+}}$ molecules in an intense 800nm nearinfrared (NIR) laser field. Combining with a synchrosqueezing transform of the quantum timefrequency spectrum and an extended semiclassical analysis, we explore indepth the roles of various quantum trajectories, including short and longtrajectories, multiphoton trajectories, resonanceenhanced trajectories, and multiple rescattering trajectories of the below and nearthreshold harmonic generation processes. Our results shed new light on the dynamical origin of the below and nearthreshold harmonic generation and various quantum trajectories for diatomic molecules. [Preview Abstract] 

D1.00111: Harmonic generation of Li atoms in Rabiflopping regime kobra Nasiri avanaki, Dmitry A. Telnov, ShihI Chu We study harmonic generation of Li atoms in one and twophoton Rabiflopping regimes where the population transfer from the ground $2s$ state to the excited $2p$, $3s$, and $3d$ states is significant. Our theoretical approach is based on the timedependent densityfunctional theory taking into account dynamic multielectron response to the external field. In the onephoton Rabiflopping regime between the $2s$ and $2p$ states, the harmonic spectrum exhibits a fine oscillatory structure, with the spacing between the adjacent subpeaks equal to twice the Rabi frequency. The structure originates from the lowfrequency modulation of the timedependent dipole moment due to oscillations of the electronic population between the $2s$ and $2p$ states. For higher laser intensities, the pattern in the harmonic spectrum becomes more complex because of the population transfer to other excited states and pulse shape effects. Using the concept of adiabatic Floquet states, we show that interference of the contributions to the harmonic signal from the leading and trailing edges of the laser pulse also results in a fine structure of the harmonic peaks but on a smaller frequency scale. Similar structures in the harmonic spectra are observed in the twophoton Rabiflopping regimes as well. [Preview Abstract] 

D1.00112: NonSequential Double Recombination High Harmonic Generation in Molecularlike Systems Kenneth Hansen, Lars Bojer Madsen Nonsequential double recombination (NSDR) high harmonic generation (HHG) is a strongly correlated twoelectron HHG process where two electrons combine their potential and kinetic energy into emitting a single photon. We have studied this process in a molecularlike system and found that the twoelectron nature of the signal results in the emitted HHG spectrum being dependent on the structure of the molecule, i.e., the nuclear configuration at ionization. A clear dependence in the NSDR HHG signal on the internuclear distance is observed in the cutoffs of the HHG spectrum for large internuclear distances where also an indication of the point of emission (the atom within the molecule from which the electrons is kicked out) can be observed in the HHG spectrum. A change in the NSDR process is observed when a change in the electron charge transfer in the molecule shifts the observed cutoffs in a process not seen in normal oneelectron HHG. [Preview Abstract] 

D1.00113: Fewcycle strongfield ionization of atomic hydrogen with elliptically polarized light. Nicolas Douguet, Klaus Bartschat We consider strongfield ionization of atomic hydrogen by elliptically polarized light in the longwavelength regime (800~nm). By solving the timedependent Schr\"odinger equation, we analyze the ionization spectra at various peak intensities up to $4 \times 10^{14}\,$W/cm$^2$. The calculations are performed with the length and velocity forms of the electric dipole operator. In particular, we compare the extreme cases of circularly and linearly (studied in~[1]) polarized light. Starting from an oriented atomic state, we also consider the dynamics responsible for circular dichroism~[2], from the multiphoton to the tunneling regime. A model based on the strongfield approximation is employed in an attempt to predict the variation of the dichroism as a function of the laser peak intensity. Finally, we analyze the tunneling time for photoionization in the strongfield regime. [1] A. N. GrumGrzhimailo, B. Abeln, K. Bartschat, D. Weflen, and T.~Urness, Phys.\ Rev. A~{\bf 81} (2010) 043408. [2] M. Ilchen {\it et al.}, Phys.\ Rev.\ Lett.~{\bf 118} (2017) 013002. [Preview Abstract] 

D1.00114: Understanding strongfield coherent control using the Parametric State Expansion Jens Svensmark, B. D. Esry The carrierenvelope phase (CEP) of an ultrashort laser pulse is $2\pi$periodic. We have shown\footnote{V. Roudnev and B. D. Esry, Phys. Rev. Lett. {\bf99}, 220406 (2007)}\textsuperscript{,}\footnote{J. J. Hua and B. D. Esry, J. Phys. B {\bf 42}, 085601 (2009)} that from this simple, almost trivial, observation the analytic dependence of any observable on the CEP can be found by expanding the wave function in a Fourier series. The Fourier index turns out to be interpretable as the photon number. From this insight, it is possible to predict when CEP effects will be most pronounced, and thus help choose parameters to maximize control via the CEP. But why stop with CEP? The same basic formulation can be applied to any parameter that influences a given problem. For instance, an elliptically polarized laser pulse can be parametrized with a $2\pi$periodic ellipticity parameter. The angle between noncollinear pump and probe pulses is similarly a periodic parameter in the Hamiltonian. The analytic dependence of observables such as the strongfield photoelectron momentum distribution on these paremeters can thus be derived. We will present these derivations and explore their interpretations, focusing on the physical insights they provide. [Preview Abstract] 

D1.00115: Timelocal equation for exact timedependent optimized effective potential in timedependent density functional theory ShengLun Liao, TakSan Ho, Herschel Rabitz, ShihI Chu Solving and analyzing the exact timedependent optimized effective potential (TDOEP) integral equation has been a longstanding challenge due to its highly nonlinear and nonlocal nature. To meet the challenge, we derive an exact timelocal TDOEP equation that admits a unique realtime solution in terms of timedependent KohnSham orbitals and effective memory orbitals. For illustration, the dipole evolution dynamics of a onedimensionmodel chain of hydrogen atoms is numerically evaluated and examined to demonstrate the utility of the proposed timelocal formulation. Importantly, it is shown that the zeroforce theorem, violated by the timedependent KriegerLiIafrate approximation, is fulfilled in the current TDOEP framework. [Preview Abstract] 

D1.00116: Strongfield ionization and fragmentation of acetylene, ethylene, and ethane E. Wells, A. Voznyuk, D.G. Schmitz, J.B. Mahowald, S.N. Tegegn, J.L. napierala, T.G. Burwitz, Bethany Jochim, M. Zohrabi, T. Severt, N.G. Kling, K.J. Betsch, Ben Berry, M.F. Kling, K.D. Carnes, I. BenItzhak Velocitymapimaging is used to examine the momentum distributions of photofragments arising from strongfield ionization of deuterated acetylene, ethylene, and ethane. The kinetic energy release and photofragment angular distributions of several dissociation processes are examined as a function of laser intensity and pulse duration. Notably, we examine elimination of one or two neutral hydrogen atoms following single ionization, the bondrearrangement processes that lead to D$_3^+$ fragments from ethane and CD$_3^+$ from ethylene, and the transition of the angular distribution of symmetric and nearsymmetric dissociation channels from alignment with the laser polarization at high laser intensity to more complex angular distributions at lower laser intensity. [Preview Abstract] 

D1.00117: Retrieving plasmonic field information from metallic nanospheres using attosecond photoelectron streaking spectroscopy Jianxiong Li, Erfan Saydanzad, Uwe Thumm Streaked photoemission by attosecond extreme ultraviolet (XUV) pulses into an infrared (IR) or visible streaking pulse, holds promise for imaging with subfs time resolution the dielectric plasmonic response of metallic nanoparticles to the IR or visible streaking pulse. We calculated the plasmonic field induced by streaking pulses for 10 to 200 nm diameter Au, Ag, and Cu nanospheres and obtained streaked photoelectron spectra by employing our quantummechanical model [1]. Our simulated spectra show significant oscillationamplitude enhancements and phase shifts for all three metals (relative to spectra that are calculated without including the induced plasmonic field) and allow the reconstruction of the plasmonic field enhancements and phase shifts for each material. [1] J. Li, E. Saydanzad, and Uwe Thumm, Phys. Rev. A 94, 051401(R) (2016). [Preview Abstract] 

D1.00118: Efficient and scalable ionization of neutral atoms by an orderly array of golddoped silicon nanowires Igal Bucay, Ahmed Helal, David Dunsky, Alex Leviyev, Akhila Mallavarapu, S.V. Sreenivasan, Mark Raizen Ionization of atoms and molecules is an important process in many applications and processes such as mass spectrometry. Ionization is typically accomplished by electron bombardment, and while it is scalable to large volumes, is also very inefficient due to the small cross section of electronatom collisions. Photoionization methods can be highly efficient, but are not scalable due to the small ionization volume. Electric field ionization is accomplished using ultrasharp conducting tips biased to a few kilovolts, but suffers from a low ionization volume and tip fabrication limitations. We report on our progress towards an efficient, robust, and scalable method of atomic and molecular ionization using orderly arrays of sharp, golddoped silicon nanowires. As demonstrated in earlier work, the presence of the gold greatly enhances the ionization probability, which was attributed to an increase in available acceptor surface states. We present here a novel process used to fabricate the nanowire array, results of simulations aimed at optimizing the configuration of the array, and our progress towards demonstrating efficient and scalable ionization. [Preview Abstract] 

D1.00119: Suppressed tunneling ionization of vanadium Xi Chu, Gerrit Groenenboom Using a time dependent density functional theory method, we reproduce the measured ionization suppression for vanadium in 1500 nm lasers of 1.4 to 2.8$\times 10^{13}$ W/cm$^2$. Our calculation shows that for weaker laser intensities a method with more configurations is needed to properly describe the multiphoton, rather than tunneling, ionization of a transition metal atom. We find two effects that suppress the tunneling ionization. One of them is the isotropic component of the induced potential, which increases the binding energy of the electron. The other is the dipole component that elevates the potential barrier of tunneling ionization. [Preview Abstract] 

D1.00120: Ionization of alkaline earth atoms in intense femtosecond laser fields Bradford Talbert, Yu Hang Lai, Xiaowei Gong, Junliang Xu, Cosmin Blaga, Pierre Agostini, Louis DiMauro Electron correlation effects in the ionization of He in the presence of strong laser fields has been extensively studied. As an alternative to He, the alkaline earth atoms are good twoelectronlike systems for studying how electron correlation effects in strong fields depend on ionization potential and atomic structure. We investigate the yields of single and double ionization of Mg and Ca as a function of intensity, and ellipticity at 0.8, 1 and 3.6 \textmu m. Of particular interest to our research is the failure of PPT to predict the double ionization yield seen in both Mg and Ca, and the apparent enhancement structure in the double ionization yield of Mg under a circularly polarized (CP) field at 0.8 \textmu m [1]. Classical trajectory simulations suggest the enhancement under a CP field is due to electron recollision [2, 3]; as a comparison to Mg, we target Ca to investigate how this phenomenon depends on ionization potential and atomic structure. \textit{[1] G. D. Gillen, et al., Phys. Rev. A 64, 043413 (1994).} \textit{[2] F. Mauger, et al., Phys. Rev. Lett. 105, 083002 (2010).} \textit{[3] L. B. Fu, et al., Phys. Rev. Lett. 108, 103601 (2012).} [Preview Abstract] 

D1.00121: Wavelength Dependence of the StrongField Ionization of Isomeric Molecules Stefan Zigo, Alberto Gonzalez Castrillo, Robert Lucchese, AnhThu Le, Carlos TralleroHerrero The ionization behavior of isomeric molecules has been studied with the aid of timeofflight mass spectroscopy (TOFMS). We study the influence of structural changes on the singly ionized strongfield ionization yields in randomly oriented C$_{4}$H$_{6}$, C$_{4}$H$_{8}$, and C$_{4}$H$_{10}$ isomers as a function of intensity. The experiments were performed with three different light sources with center wavelengths of 800, 1320, and 1940 nm with pulse duration of 30, 50, and 150 fs, respectively. The isomeric pairs range from small to large changes in structure creating differences in the molecular properties, such as, orbital shape and ionization potential. This allows for the investigation of the influence of these property changes on single ionization in a broader range of conditions. In addition, the experimental results serve as a benchmark for current molecular ionization theories. This proposal was supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy (DOE). [Preview Abstract] 

D1.00122: Exploration of laserdriven electronmultirescattering dynamics in highorder harmonic generation PengCheng Li, ShihI Chu We investigate the dynamical origin of multiple rescattering processes in highorder harmonic generation (HHG) associated with the odd and even number of returning times of the electron to the parent ion. We perform fully \textit{ab initio }quantum calculations and extend the empirical mode decomposition method to extract the individual multiple scattering contributions in HHG. We~find that the tunneling ionization regime is responsible for the odd number times of rescattering and the corresponding short trajectories are dominant. On the other hand, the multiphoton ionization regime is responsible for the even number times of rescattering and the corresponding long trajectories are dominant. Moreover, we discover that the multiphoton and tunnelingionization regimes in multiple rescattering processes occur alternatively. Our results uncover the dynamical origin of multiple rescattering processes in HHG for the~first time. It also provides new insight regarding the control of the multiple rescattering processes for the optimal generation of ultrabroad band supercontinuum spectra and the production of single ultrashort attosecond laser pulse. [Preview Abstract] 

D1.00123: Threedimensional momentum imaging of dissociation in flight of metastable molecular ions Bethany Jochim, Reid Erdwien, T. Severt, Ben Berry, Peyman Feizollah, Jyoti Rajput, Y. Malakar, B. Kaderiya, W. L. Pearson, K. D. Carnes, A. Rudenko, I. BenItzhak While fragmentation of molecular ions induced by ultrashort laser pulses or fast ions often proceeds on femtosecond timescales, the population of metastable states can lead to decay on much longer timescales, ranging from picoseconds to even seconds [1,2]. We examine in detail the unimolecular dissociation in flight of such longlived metastable molecular ions, utilizing the cold target recoil ion momentum spectroscopy (COLTRIMS) technique. Via the example of deprotonation of metastable ethylene dications formed in intense femtosecond laser pulses, we demonstrate a method that allows retrieval of the lifetime(s) of the metastable states, as well as the 3D momentum distributions of the dissociating fragments. Importantly, our approach is general and can be used to study other heteronuclear metastable molecules that undergo dissociation in flight. \\ \\ {[1]} S. D. Price, Int. J. Mass Spectro. \textbf{260}, 1 (2007). \\ {[2]} D. Mathur, Phys. Rep. \textbf{391}, 1 (2004). [Preview Abstract] 

D1.00124: Imaging threebody breakup involving two identical fragments Peyman Feizollah, T. Severt, Bethany Jochim, Ben Berry, Kanaka Raju P., M. Zohrabi, Jyoti Rajput, U. Ablikim, B. Kaderiya, Farzaneh Ziaee, A. Rudenko, D. Rolles, K. D. Carnes, B. D. Esry, I. BenItzhak We study the strongfield fragmentation of CO$_2$ and CO$_2$$^+$ into C$^+$+O$^+$+O$^+$ as examples of threebody breakup involving two identical fragments. This process can happen through concerted or sequentialbreakup mechanisms. In concerted breakup, the two O$^+$ fragments play indistinguishable roles. In sequential breakup, however, one of the O$^+$ fragments comes from the first fragmentation step of CO$_2$$^{3+}$, and the other one comes from unimolecular dissociation of CO$^{2+}$ in the second step. Therefore, in sequential breakup the two O$^+$ fragments may be distinguished. A method is proposed that allows us to separate the concerted and sequential processes when the lifetime of the intermediate molecule is much longer than its rotational period. As a result, it is possible to experimentally distinguish the two O$^+$ fragments in the sequential process. [Preview Abstract] 

D1.00125: Extracting the wavepacket phase in Highorder Harmonic Generation with a homodyne interferometer. Georgios Kolliopoulos, Jan Tross, Carlos TralleroHerrero A novel selfreferencing XUV interferometer is used as a tool of extreme sensitivity to below attosecond stability. Using a liquid crystal phase modulator, two spatially distinct highorder harmonic sources are induced with control on their relative brightness. The radiations from these two sources interfere in the far field providing a highly versatile implement for EUV interferometry. With this tool, we investigate the dependence of the phase of highorder harmonics on the driving field intensity. Our results are compared with theoretical and experimental reports in the existing scientific literature. The error estimates are improved and help to draw a clear picture of the intensity dependent atomic dipole phase in the process of highorder harmonic generation, as expected from the threestep model. However, we observe differences from the strong field approximation: loworder harmonics with photon energies below or near the ionization potential show also a phase dependence on the driving field intensity and a study of HHG driven by pulses in intensity regimes, where saturation effects become important, shows a deviation from the model. This behavior is radically different from what was observed for higher order harmonics. [Preview Abstract] 

D1.00126: PHOTOIONIZATION, PHOTODETACHMENT AND PHOTODISSOCIATION 

D1.00127: Photoionization of openshell Cl@C$_{\mathrm{60}}$ Dakota Shields, Ruma De, Mohamed Madjet, Steven T. Manson, Himadri Chakraborty The ground state of the atomically openshell Cl@C$_{\mathrm{60}}$ endofullerene molecule is modeled in a spherical local density approximation (LDA) augmented by the Leeuwen and Baerends exchangecorrelation functional [1] where the core of sixty C$^{\mathrm{4+}}$ ions is jelliumized [2]. A timedependent LDA (TDLDA) method is subsequently applied to calculate the dipole photoionization parameters of the endohedral molecule. Cross sections for the photoemission from atomfullerene hybrid levels show the effects of both C$_{\mathrm{60}}$ plasmon and atomic Coulomb dynamics, as well as the interference between them. At higher energies, the coherence of confinement and cavity oscillations dominates the structures of the spectra. Detailed comparison with the results from Ar@C$_{\mathrm{60}}$, which involves the nearby closeshell atom in the periodic table, provides deeper insights into the role of a single shellclosing electron to noticeably influence the ionization dynamics. [1] R. van Leeuwen et al, Phys. Rev. A \textbf{49}, 2421 (1994); [2] M. E. Madjet et al., Phys. Rev. A \textbf{81}, 013202 (2010). [Preview Abstract] 

D1.00128: Impact of nondipole effects on spinpolarization of photoelectrons from fullerene anions A. Edwards, C. Lane, V. Dolmatov The present work provides the initial insight into the impact of a nondipole part of lowphotonenergy photodetachment on the degree of spinpolarization (SP) of photoelectrons from fullerene anions C$_{N}^{}$. This problem is interesting. A fullerene anion has a much bigger size than that of a free atom, and a C$_{N}$ cage is a resonator to the outgoing photoelectron wave. All this might increase significantly the impact of nondipole effects on the degree of photoelectron's SP from C$_{N}^{}$s. The study focuses on the impact of an electric dipolequadrupole (E1E2) part of photodetachment on the degree of photoelectron's SP from C$_{N}^{}$s with progressively increasing sizes: $N =60$, 240, 540, and 1500. The focus is on a very low, only fewtenseV photonenergy domain. Different photoelectron angular and spingeometries are considered. Calculations are performed in a model approximation, where a C$_{N}$ cage is modeled by a sphericalwell potential. It is demonstrated that the contribution of E1E2 effects to the the degree of photoelectron's SP from C$_{N}^{}$s can be on the order of $10\%$, at certain energies. Importantly, this is found to occur at only few\underline{tenseV}photonenergy, in contrast to \underline{hundredseV}photonenergy in the case of atoms. [Preview Abstract] 

D1.00129: Double Photoionization of Neon atoms using screening potential approach Hari P. Saha We will report the results of triple differential cross section for double photoionization of raregas atom, neon using our extended MCHF method [ 1]. It is well known that electron correlation effects in both the initial and the final states are very important. To incorporate these effects we will use both HartreeFock and multiconfiguration HartreeFock methods to account for electron correlation in the initial state. The electron correlation in the final state will be taken into account using the angledependent screening potential approximation [2,3]. Our results will be compared with available experimental observations and accurate theoretical calculations . [1] Hari P. Saha, J. Phys. B 47, 175005 (2014). [2] M.R.H. Rudge, Rev. Mod. Phys. 40, 564 (1968). [3] C.Pan and A.F Starace, Phys. Rev. Lett. 67, 185 (1991); Phys. Rev. A45, 4588 (1992). [Preview Abstract] 

D1.00130: Double photoionization of Kshell electrons of Beryllium atoms using affective charge approximation. Hari P. Saha We plan to report the results of our investigation on double photoionization Kshell electrons from Beryllium atoms. We will present the results of triple differential cross sections at excess energy of 40 eV using our recently extended MCHF method [1]. We will use multiconfiguration Hartree Fock method to calculate the wave functions for the initial state. The final state wave functions will be obtained in the angle depended Effective Charge approximation [24] which accounts for electron correlation between the two final state continuum electrons. We will discuss the effect of core correlation and the valence shell electrons in the triple differential cross section. The results will be compared with the available accurate theoretical calculations and experimental findings. [1] Hari P. Saha, Phys. Rev. A 87, 042703 (2013). [2] M.R.H. Rudge, Rev. Mod. Phys. 40, 564 (1968). [3] D. Proulox and R. Shakeshaft,, Phys. Rev A 48, R875 (1993). [4]; M. Pont and R. Shakeshaft, Phys. Rev. A51, R2676 (1995). [Preview Abstract] 

D1.00131: Photoionization and scattering amplitudes for polyatomic molecules using the overset grid complex Kohn variational method Loren Greenman, Robert R. Lucchese, C. William McCurdy Recent attosecond dynamics experiments [Calegari, et. al., Science 346, 336 (2014)] and coincidence experiments that measure molecular frame photoionization angular distributions [McCurdy, et. al., Phys. Rev. A 95, 011401(R) (2017)] can be explained using photoionization amplitudes calculated by the complex Kohn variational method (along with timedependent perturbation theory), although such methods with channel coupling and exchange have so far been limited to small molecules. We have recently overcome this limitation, in large part by using overset grids. These are composed of multiple atomcentered subgrids in addition to a central master grid, with switching functions that partition wavefunctions between grids. We present here the extension of the overset grid complex Kohn variational method to photoionization and to multichannel electron scattering, along with results for the photoionization of SF6 and electron scattering in the RNA base uracil. [Preview Abstract] 

D1.00132: Virtual detector methods for efficiently computing ionization and dissociating spectra Alex Kramer, Uwe Thumm We discuss a fluxbased ``virtual detector'' method for computing momentumresolved dissociation and ionization spectra by analyzing the motion of quantum mechanical wavepackets at the periphery of their numerical grids. We extended prior semiclassical applications of this method [14] by systematically including quantum mechanical corrections. Using examples of atomic ionization and diatomic molecular dissociation, we discuss the numerical convergence properties and computational efficiency of this computational method. We also compare the numerical efficiency of virtual detection to Fourier transformation methods for extracting momentum spectra from timedependent quantum mechanical calculations. [1] Feuerstein, B. and U. Thumm, J. Phys. B \textbf{36}, 707 (2003). [2] Magrakvelidze, M. \textit{et al.}, Phys. Rev. A \textbf{86}, 023402 (2012). [3] Wang. X. \textit{et al.,} Phys. Rev. Lett. \textbf{110}, 243001 (2013). [4] Teeny, N. \textit{et al.,} Phys. Rev. A \textbf{94}, 022102 (2016). [Preview Abstract] 

D1.00133: Orientation and alignment of excited molecular photoions from the polarization of their fluorescence Alberto GonzalezCastrillo, Robert Lucchese We examine the fluorescence of the photoionized nitrogen molecule, with linearly and circularlypolarized incident light: $\mathrm{N}_2 (X ^1\Sigma_g^+) + \gamma \rightarrow \mathrm{N}_2^+ (B ^2\Sigma_u^+,J') +e^(\epsilon\pi_g,\epsilon\sigma_g)\rightarrow \mathrm{N}_2^+ (X ^2\Sigma_g^+,J'') +\gamma'$. First, we compute the rotational specific transition as a function of the molecular orientation and the incident light polarization. Then, we investigate the fluorescence process from the intermediate molecular photoion reached in the first step, focusing on the dependence of the fluorescence intensity with the polarization parameters of both incident and emitted light. The computed fluorescence intensity, as a function of its polarization parameters, is compared to the experimental results obtained by J. E. Furst {\it et al.} Both experimental and theoretical results show that the residual molecular photoion, $\mathrm{N}_2^+ (X ^2\Sigma_g^+,J'')$, is oriented and this is generally opposite to the direction reached in the simple excitation of the N$_2$ by the absorption of circularlypolarized light. This clearly indicates that the ejected electron in the ionization process carries away most of the free angular momentum in the collision. [Preview Abstract] 

D1.00134: Molecular frame and recoil frame photoelectron angular distributions from dissociative photoionization of NO$_2$ including the effects of rotation Richard Carranza, Robert Lucchese We report the computed molecular frame photoelectron angular distributions and recoil frame photoelectron angular distributions, taking into account the influence of rotation between ionization and dissociation, for the singlephoton ionization of the nonlinear NO$_2$ molecule leading to the $(1a_2)^{1} b\ ^3A_2$ and $(4a_1)^{1} \ ^{3}A_1$ states of NO$_2^+$. Additionally, we report the effects of channel coupling by employing the Complex Kohn variational method and comparing the results to computed singlechannel photoionization cross sections. By comparing computed and measured photoionization cross sections we can estimate an upper bound to the lifetime of the initially produced ion state with respect to dissociation. [Preview Abstract] 

D1.00135: Classical trajectory studies on the dynamics of onephoton double photionization of H$_2$O Zachary Streeter, Frank Yip, Dylan P. Reedy, Allen Landers, C. William McCurdy Recent momentum imaging experiments at the Advanced Light Source have opened the possibility of measuring the complete triple differential cross section (TDCS) for onephoton double ionization of H$_2$O in the molecular frame. The measurements depend on the complete breakup process, H$_2$O $+ h\nu \rightarrow$ 2e$^$+ H$^+$ + H$^+$ +O. At the 57 eV photon energy of the experiment this process could proceed via any of the nine energetically accessible electronic states of H$_2$O$^{++}$. To discover which ionization channels contribute to the observed TDCS for the electrons measured in coincidence with different kinetic energy releases, we have carried out classical trajectory studies for breakup of the water dication on all nine potential surfaces, sampling from a Wigner phase space distribution for the vibrational ground state of H$_2$O. The final momentum distributions of the protons and branching ratios between two and threebody breakup are then analyzed and the results are compared with experiment to identify which ionization channels contribute to the TDCS observed in coincidence measurements of the ejected electrons. [Preview Abstract] 

D1.00136: Dynamic Effects in the Photoionization of the 6s Subshell of Radon and Nobelium David Keating, Steven Manson, Pranawa Deshmukh Relativistic interactions are very important contributors to atomic properties. Of interest is the alterations made to the wave functions, i.e., the dynamics. These dynamical changes can greatly affect the photoionization cross section of heavy (high Z) atoms. To explore the extent of these dynamic effects a theoretical study of the 6s photoionization cross section of both radon (Z $=$ 86) and nobelium (Z $=$ 102) have been performed using the relativistic random phase approximation (RRPA) methodology [1]. These two cases have been selected because they offer the clearest picture of the effects in question. In order to determine which features in the photoionization cross section are due to relativity, calculations using the (nonrelativistic) random phase approximation with exchange method (RPAE) [2] are performed for comparison. Interchannel coupling can obscure the dynamic effects by ``pulling'' minima out of the discrete spectrum and into the continuum or by inducing minima. Therefore it is necessary to perform calculations without coupling included. This is possible thanks to the RRPA and RPAE codes being able to calculate cross sections with particular channels omitted. Comparisons are presented between calculations with and without interchannel coupling. Work supported by DOE and NSF. [1] W. R. Johnson and C. D. Lin, Phys. Rev. A 20, 964 (1979); [2] M. Ya. Amusia, Atomic Photoeffect (Plenum, NY, 1990). [Preview Abstract] 

D1.00137: Relativistic Confinement Resonances David Keating, Steven Manson, Pranawa Deshmukh Photoionization of confined atoms in a C60 fullerene have been under intense investigation in the recent years, in particular the confinement induced resonances, termed confinement resonances. The effects of the C60 potential are modeled by a static spherical well, with (in atomic units) inner radius r0 $=$ 5.8, width $\Delta \quad =$ 1.9, and depth U0 $=$ 0.302, which is reasonable in the energy region well above the C60 plasmons [1]. At very high Z, relativistic interactions become important contributors to even the qualitative nature of atomic properties; this is true for confined atomic properties as well. To explore the extent of these interactions, a theoretical study of several heavy atoms has been performed using the relativistic random phase approximation (RRPA) methodology [2]. In order to determine which features in the photoionization cross section are due to relativity, calculations using the (nonrelativistic) random phase approximation with exchange method (RPAE) [3] are performed for comparison. The existence of the second subshell of the spinorbitsplit doublets can induce new confinement resonances in the total cross section, which is the sum of the spinorbitsplit doublets, due to the shift in the doublet's threshold. Several examples for confined highZ atoms are presented. Work supported by DOE and NSF. [1] V. K. Dolmatov, Adv. Quantum. Chem. 58, 13 (2009); [2] W. R. Johnson and C. D. Lin, Phys. Rev. A 20, 964 (1979); [3] M. Ya. Amusia, Atomic Photoeffect (Plenum, NY, 1990). [Preview Abstract] 

D1.00138: Fingerprints of corehole localization in the inner shell ionization of carbon tetrachloride B. Gaire, P. Stammer, A. Gatton, B. Berry, T. Severt, J. Rist, S. Eckart, J. Williams, I. BenItzhak, R. Doerner, Th. Weber We present innershell photoionization studies of single carbon tetrachloride molecules by ionizing electrons from the chlorine 2p orbital applying our COLTRIMS method, which we recently upgraded to accommodate low vapor pressure samples in the liquid form. Recoil frame photoelectron angular distributions (RFPADs) are generated by transforming the measured coincident electronion 3Dmomentum vectors to body fixed frames. The RFPADs for the most prominent two ionic breakup channel are presented for three different photoelectron energies and orientations of the polarization direction of the incoming light with respect to the recoil axis. The asymmetric and rich structures of the electron emission patterns suggest the localization of the core hole at the Cl atom from which the 2p electron was released, similar to the case of the F Kshell ionization of carbon tetrafluoride where, in close collaboration with theory, a strong unambiguous core hole localization effect was identified. [Preview Abstract] 

D1.00139: Photoionization of atomic chlorine near the Kedge Z. Felfli, S. T. Manson, A. Z. Msezane The photoionization cross section for atomic Cl in the vicinity of the 1s threshold has been investigated using Rmatrix methodology. Specifically, the resonances leading up to the first two 1s ionization thresholds, the 1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{5}}$ $^{\mathrm{3,1}}$P states of Cl$^{\mathrm{+}}$,$^{\mathrm{\thinspace }}$have been examined in detail. In addition to the 1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{6}}$ $^{\mathrm{2}}$S resonance, which arises from a 1s$\to $3p transition that is possible owing to the open shell nature of the Cl atom, there are six resonances series leading up to the two thresholds: \textbraceleft 1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{5}}$ $^{\mathrm{3,1}}$P\textbraceright np $^{\mathrm{2}}$S, $^{\mathrm{2}}$P, $^{\mathrm{2}}$D. The results show that the 1s$\to $3p resonances is by far the strongest, as might be expected, and the energy and shape are in rather good agreement with experiment [1]. Furthermore, this lowest $^{\mathrm{2}}$S resonance ``robs'' oscillator strength from the resonances of the \textbraceleft 1s2s$^{\mathrm{2}}$2p$^{\mathrm{6}}$3s$^{\mathrm{2}}$3p$^{\mathrm{5}}$ $^{\mathrm{3}}$P\textbraceright np $^{\mathrm{2}}$S series, which are very much weaker than their $^{\mathrm{2}}$P and $^{\mathrm{2}}$D counterparts; there is no 1s$\to $3p resonance in the $^{\mathrm{2}}$P and $^{\mathrm{2}}$D manifolds. The next strongest resonances are the six 1s$\to $4p excitations. Each pair $^{\mathrm{2}}$S, $^{\mathrm{2}}$P and $^{\mathrm{2}}$D n$=$4 resonances interact so that their separation is not the splitting of the $^{\mathrm{3}}$P and $^{\mathrm{1}}$P 1s ionization thresholds, and their quantum defects are very much larger than the asymptotic values and for the n$=$4, they are about 1.6 for the $^{\mathrm{2}}$P and $^{\mathrm{2}}$D while for the $^{\mathrm{2}}$S they are about 1.8, reflecting the fact that the n$=$4 $^{\mathrm{2}}$S resonances are also strongly affected by the 1s3p$^{\mathrm{6}}$ resonance; the higher resonances in all series exhibit quantum defects of about 0.9. [1] W. C. Stolte, \textit{et al}, Phys. Rev. A \textbf{88}, 053425 (2013). Work supported by U.S. DOE. [Preview Abstract] 

D1.00140: Isomerization of Ethanol Induced by Synchrotron Radiation Nora G. Kling, Razib Obaid, Utuq Ablikim, Sven Augustin, Balram Kaderiya, Stefan Zigo, Ileana Dumitriu, Kirsten Schnorr, Timur Osipov, Rene Bilodeau, Daniel Rolles, Nora Berrah We have carried out a synchrotronbased Xrayinduced hydrogenmigration experiment in ethanol (CH$_{\mathrm{3}}$CH$_{\mathrm{2}}$OH) using the photoionphotoion coincidence (PIPICO) technique at the Advanced Light Source. A photon energy of 312 eV, situated above the carbon Kedge, ensures that predominantly C(1s) electrons are ionized. This innershell ionization induces both single and double hydrogen migration from the carbon sites to the oxygen site, evidenced in our coincidence maps that display the observed channels, including H$_{\mathrm{2}}$O$^{\mathrm{+}} \quad +$ C$_{\mathrm{2}}$H$_{\mathrm{3}}^{\mathrm{+}} \quad +$ H$^{\mathrm{+/0}}$ and H$_{\mathrm{2}}$O$^{\mathrm{+}} \quad +$ C$_{\mathrm{2}}$H$_{\mathrm{2}}^{\mathrm{+}} \quad +$ 2H$^{\mathrm{+/0}}$/$^{\mathrm{\thinspace }}$H$_{\mathrm{2}}^{\mathrm{+/0}}$. The presence of the water ion indicates that at least one hydrogen atom has migrated. We will present the 3D momenta of these and other relevant channels. [Preview Abstract] 

D1.00141: Absolute single photoionization cross section measurements of Rb$^{\mathrm{2+}}$ and Rb$^{\mathrm{3+}}$ ions: experiment and theory Daniel Rogers, David Macaluso, Allison Mueller, Andrea Johnson, Kyren Bogolub, Alex Aguilar, A.L. David Kilcoyne, Rene Bilodeau, Manuel Bautista, Austin Kerlin, Nicholas Sterling Absolute single photoionization crosssection measurements of Rb$^{\mathrm{2+}}$ and Rb$^{\mathrm{3+}}$ ions were performed using synchrotron radiation and the photoion, mergedbeams technique at the Advanced Light Source at Lawrence Berkeley National Laboratory. Measurements of Rb$^{\mathrm{2+}}$ were made at a photon energy resolution of 13.5 meV from 37.31 to 44.08 eV spanning the $^{\mathrm{2}}$P$_{\mathrm{3/2\thinspace }}$ground state and $^{\mathrm{2}}$P$_{\mathrm{1/2\thinspace }}$metastable state ionization thresholds. Measurements of Rb$^{\mathrm{3+}}$ were made at a photon energy resolution of 30.0 meV from 49.50 to 62.49 eV spanning the $^{\mathrm{3}}$P$_{\mathrm{2}}$ ground state and $^{\mathrm{3}}$P$_{\mathrm{1,0}}$, $^{\mathrm{1}}$D$_{\mathrm{2}}$, and $^{\mathrm{1}}$S$_{\mathrm{0}}$ metastable state ionization thresholds. Multiple autoionizing resonance series arising from both parent ions are identified using quantum defect theory. The measurements are compared to BreitPauli Rmatrix calculations. [Preview Abstract] 

D1.00142: Commission of a new 2color lasersynchrotron COLTRIMS experiment A. Gatton, K. Larsen, E. Champenois, N. Shivaram, S. Bakhti, W. Iskander, T. Sievert, D. Reedy, M. Weller, J.B. Williams, A. Landers, Th. Weber We present the technical scheme of a new 2color laser + synchrotron Cold Target Recoil Ion Momentum Spectrometer (COLTRIMS) experiment in which we overlap a pulsed IR laser ($1MHz$, $1030nm$, $12ps$, $5*10^{11}W/cm^2$) with XUV light from beamline 10.0.1 ($3MHz$, $18.56eV$, $80ps$, $50meV$ resolution) at the Advanced Light Source (ALS) at Lawrence Berkeley National Lab. We discuss the experimental methods for overlapping in 3D the colinear ALS beam ($80um \times 100um$) with the laser beam focus ($50um \times 50um$) inside the gas jet target with a horizontal length and depth of $1mm$, as well as the timing scheme for achieving sub nanosecond stable synchrolock of the two pulse trains such that they are overlapped in time at the gas jet target every third ALS pulse. We present a definitive 2 color signal observed in Helium excited by $23.74eV$ photons from the ALS to the 1s4p 1P state, and then ionized by the laser. We intend to use this scheme to study dissociation dynamics of excited molecules in the presence of a strong laser field. [Preview Abstract] 

D1.00143: Strong field studies of F$_2^$ dissociation and photodetachment* Ben Berry, Bethany Jochim, T. Severt, Peyman Feizollah, Kanaka Raju P., K. D. Carnes, B. D. Esry, I. BenItzhak While molecular anions have long been used as tools to investigate molecular dynamics, very few studies focus on their behavior in a strong field. In this work, we explore the strong field dissociation and photodetachment of F$_2^$ under a variety of laser conditions. The use of a keV beam of F$_2^$ allows us to measure all of the molecular fragments except electrons, and we obtain the full 3D momentum of breakup using a coincidence 3D momentum imaging technique. Past measurements of photoelectrons from F$_2^$ resulted in some uncertainty about the photoemission mechanisms due to unknown nuclear dynamics$^1$. Our measurements of the final nuclear products (both F$_2$ and F + F) help clarify the underlying physics associated with this previous study. In addition, we identify dissociation pathways and use the measured kinetic energy release (KER) to evaluate the initial rovibrational population of the anion. \\ $^1$ Hannes Hultgren and Igor Yu. Kiyan, Phys. Rev. A \textbf{84}, 015401 (2011). \\ * This work was supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. [Preview Abstract] 

D1.00144: The Iron Project \& Opacity Project: Photoionization, radiative transitions of iron ions for Opacities and Astrophysical Applications Lianshui Zhao, Sultana Nahar, Anil Pradhan, Werner Eissner We have carried out converged close coupling RMatrix (CCCRM) calculations for photoionization of Nelike Fe~XVII and demonstrate ordersofmagnitude enhancements in cross section due to successive core excitations. Convergence criteria are: (i) inclusion of sufficient number of residual ion Fe~XVIII core states, (ii) highresolution of myriad autoionizing resonances, and (iii) highenergy cross sections. We discuss verification of the conventional oscillator strength sumrule in limited energy regions for boundfree plasma opacity. High energy cross sections are also under investigation. In order to obtain solar iron opacity at the boundary of the radiative and convection zones, we have studied the residual ion states that should provide convergence of resonances of other Lshell iron ions, Fe~XIV  Fe XX, in the plasma region. Preliminary results from Rmatrix calculations of photoionization cross sections will be reported. [Preview Abstract] 

D1.00145: Experimental Measurements of the Electron Affinity of Gallium and Fine Structure of Ga$^{\mathrm{\mathbf{}}}$ N.D. Gibson, C.W. Walter, C.T. Crocker, W. Nakayama, J. Wang, J.N. Yukich The electron affinity of gallium and the negative ion fine structure splittings of Ga$^{\mathrm{\mathbf{}}}$ have been measured using tunable laser photodetachment threshold spectroscopy. The relative cross sections for neutral atom production were measured with a crossed laserion beam apparatus over the photon energy range 0.27  0.41 eV. An $s$wave threshold was observed due to the opening of the Ga$^{\mathrm{\mathbf{}}}$ (4$p^{\mathrm{2}} \quad^{\mathrm{3}}P_{\mathrm{0}})$ to Ga (4$p$ $^{\mathrm{2}}P_{\mathrm{1/2}})$ groundstate to groundstate transition, yielding a preliminary value for the Ga electron affinity. $s$wave thresholds were also observed for detachment from the J $=$ 1 and J $=$ 2 excited levels of Ga$^{\mathrm{\mathbf{}}}$, yielding preliminary values for the fine structure splittings. The present value of the electron affinity, determined by tracking contributions from multiple channels, is found to be much lower than previous experimental results [1, 2] and is in better agreement with recent theory [35]. [1] W. W. Williams \textit{et al}., J. Phys. B \textbf{31}, L341 (1998). [2] T. Andersen \textit{et al.}, J. Phys. Chem. Ref. Data \textbf{28}, No. 6, 1511 (1999). [3] D. Sundholm \textit{et al.}, J. Phys. B \textbf{32,} 5853 (1999). [4] J. Li\textit{ et al.}, J. Phys. B \textbf{45} 16500 (2012). [5] Z. Felfli, \textit{et al.}, J. Phys. B \textbf{45 }045201 (2012). [Preview Abstract] 

D1.00146: Contribution of Autoionization Process on the Double Ionization Fragmentation Channel of Carbon Dioxide Molecule Wael Iskandar, Averell Gatton, Bishwanath Gaire, Elio Champenois, Kirk Larsen, Niranjan Shivaram, Travis Severt, Ali Moradmand, Joshua Williams, Daniel Slaughter, Thorsten Weber We have studied the autoionization process happened in CO$_{2}$ molecule using photon energy below and above the double ionization threshold and a COLTRIMS setup. By populating an excited state of CO$_{2}$$^{+}$, transition may occur at the crossing point with CO$_{2}$$^{2+}$ leading to dissociation into CO$^{+}$ + O$^{+}$. By measuring in coincidence the kinetic energy release of the two ionic fragments and the energy of the two electrons detected, we are able to determine the internuclear distance at which the transition point between the intermediate state CO$_{2}$$^{+*}$ and the final state CO$_{2}$$^{2+}$ occurs. Preliminary results show very large internuclear distance at the transition point and that this latter autoionization may occurs at one order of magnitude larger than the (COO) equilibrium distance. [Preview Abstract] 

D1.00147: Multiphoton dissociation of Coronene Carmen Cisneros, Francisco Betancourt, Juan Carlos Poveda, Ignacio Alvarez, Alfonso Guerrero The multiphotoionization and multiphotodissociationof Coronene (C24H12) induced by laser interaction were analyzed with a Time of Flight Mass Spectrometer in reflectron mode. A beam of molecules was synchronized with laser radiation of 266nm with intensities between $\mbox{1.7}\times \mbox{10}^{\mbox{9}}$and$\mbox{2.7}\times \mbox{10}^{\mbox{10}}W/cm^{\mbox{2}}$. The resolution reached allowed to identify more than 300 ions, produced by the photofragmentation. The analysis of relative currents, by ion groups and by specific ions, allowed the experimental verification of dissociationroutes where prevail products CnHm with $n=\mbox{16}\mbox{24}$for low intensities, and $n=\mbox{1,2,3,4}$for high intensities. At low intensities, the presence of C16H4, C16H10, C16H12, C17H6, C17H8, C22H2, C23H4, C23H8, C24H6, C24H8, C24H10, C24H12 ions are remarkable. In addition, ions with mass greater than 300 accounts for the presence of Coronene clusters. The present work was supported by grant PAPIIT UNAM grants IN101215 and IN102516. [Preview Abstract] 

D1.00148: ATOMATOM AND ATOMMOLECULE COLLISIONS 

D1.00149: Controlling the interactions of veryhighn strontium Rydberg atoms R.G. Fields, F.B. Dunning, S. Yoshida, J. Burgdӧrfer Earlier studies have demonstrated that high $n$,$ n $ 300$,$ Rydberg states can be manipulated with remarkable precision using one, or more, short halfcycle pulsed electric fields (HCPs). In the present work many body dynamics of interacting Rydberg systems is exploited to create an initial train of approximately equispaced high $n$ Rydberg atoms in an atomic beam. Their mutual interactions are then increased using HCPs to excite them to states of much higher $n$, the degree of coupling being tuned by varying the final target state. Interest centers on energy exchange and ionization, and their dependence on the degree of interaction. The effects of interactions are monitored through changes in the atomic field ionization spectra and through the loss of Rydberg atoms from the beam. Understanding the details of RydbergRydberg interactions promises to allow creation of longlived Rydberg atom ensembles where, due to their correlated motions, the excited electrons remain far apart . [Preview Abstract] 

D1.00150: Patterned Complexity in Atomic Scattering Paul Julienne, Brandon Ruzic, John Bohn As the constituents of cold gaseous matter continue to grow in complexity, the necessity to understand their basic collision processes remains. Exotic atomic species like erbium and dysprosium have been cooled to ultracold temperatures, revealing a dense forest of chaotically distributed resonances, a much more complicated landscape than the broad, isolated resonances seen in alkaliatom systems. Nevertheless, broad resonances emerge from the chaos. These resonances correspond to special longrange eigenstates of the mixed dipolar plus van der Waals potential, which seem to occur in a predictable pattern. In this study, we describe a simple and powerful quantum defect theory for atomic scattering, how this theory can simply describe chaotic collisions, and how this theory helps illuminate the character of these special eigenstates. [Preview Abstract] 

D1.00151: Rate constants for the formation of SiO by radiative association Mark Cairnie, Robert Forrey, James Babb, Phillip Stancil, Brendan McLaughlin High quality molecular data for the lowlying states of SiO are computed and used to calculate rate constants for radiative association of Si and O. Einstein Acoefficients are also calculated for transitions between all of the bound and quasibound levels for each molecular state. The radiative widths are used together with elastic tunneling widths to define effective radiative association rate constants which include both direct and indirect (inverse predissociation) formation processes. The indirect process is evaluated for two kinetic models which represent limiting cases for astrophysical environments. The first case assumes an equilibrium distribution of quasibound states and would be applicable whenever collisional and/or radiative excitation mechanisms are able to maintain the population. The second case assumes that no excitation mechanisms are available which corresponds to the limit of zero radiation temperature and zero atomic density. Rate constants for SiO formation in realistic astrophysical environments would presumably lie between these two limiting cases. [Preview Abstract] 

D1.00152: Fulldimensional Quantum Calculations of Rovibrational Transitions in CS induced by H$_2$ Benhui Yang, Peng Zhang, Phillip Stancil, J. Bowman, N. Balakrishnan, R. Forrey Carbon monosulfide (CS), the sulfur analogue of carbon monoxide, has been widely observed in a variety interstellar regions. An accurate prediction of its abundance requires collisional rate coefficients with ambient gases. However, the collisional rate coefficients are largely unknown and primarily rely on theoretical scattering calculations. In interstellar clouds, the dominant collision partner is H$_2$. Rate coefficient data on CSH$_2$ collisions are limited to pure rotational transitions and no data exist for rovibrational transitions. In this work we evaluate the first fulldimensional potential energy surface for the CSH$_2$ system using highlevel electronic structure theory and perform explicit quantum closecoupling calculations of rovibrational transitions in CS induced by H$_2$ collisions. Cross sections and rate coefficients for rotational transitions are compared with previous theoretical results obtained within a rigidrotor model. For rovibrational transitions, statetostate rate coefficients are evaluated for several lowlying rotational levels in the first excited vibrational level of CS. Results are presented for both paraH$_2$ and orthoH$_2$ collision partners. [Preview Abstract] 

D1.00153: Electric field controlled collisions between polar molecules and Rydberg atoms Martin Zeppenfeld, Ferdinand Jarisch Controlling collisions and chemical reactions via external electric or magnetic fields provides unprecedented control over such processes, with applications including Feshbach association of ultracold molecules from ultracold atoms. We present electric field controlled collisions between polar molecules and Rydberg atoms. State changing collisions between polar molecules and Rydberg atoms are mediated by F\"orster resonant energy transfer. Changing the resonance condition via electric fields allows the collision cross section to be varied. Our work is a first step towards quantum control of hybrid moleculeRydbergatom systems, with possible applications including efficient nondestructive detection of polar molecules[1]. [1] M. Zeppenfeld, arXiv:1611.08893 [physics.atomph] (2016). [Preview Abstract] 

D1.00154: Quantum chaos analysis of energy and resonant spectra of ultracold molecules Lucie Augustovicova, John Bohn Quantum chaos that appears in ultracold collisions of highly magnetic lanthanide atoms is investigated, using both realistic models of dysprosium atoms and a schematic model. Our model of dyprosium spectra includes an anisotropic interaction potential that scrambles Zeeman levels, and whose presence reveals degrees of chaos even for partial interaction strength. We perform statistical analyses of the energy spectrum at B$=$0 as well as the spectrum of magnetic field FanoFeshbach resonances at E$=$0. We find that chaos is preserved in the mapping from energy spectra to magnetic field spectra within fit uncertainty. The relation between these two spectra is semiquantitatively studied within a model based on a spin Hamiltonian, mixed by potential matrices drawn at random from a Gaussian orthogonal ensemble.~ This work was supported by an AFOSR MURI grant. [Preview Abstract] 

D1.00155: Threeatom recombination through a narrow Feshbach resonance in $^6$Li Jiaming Li, Leonardo de Melo, Le Luo, Bo Gao We experimentally measure, and theoretically analyze the threeatom recombination rate, $L_3$, around a narrow $s$ wave magnetic Feshbach resonance of $^6$Li$^6$Li around 543.3 Gauss. By examining both the magnetic field dependence and especially the temperature dependence of $L_3$ over a wide range of a few $\mu$K to 200 $\mu$K, we show that threeatom recombination through a narrow resonance follows a universal behavior as determined by the longrange van der Waals potential, and can be described by a set of rate equations in which threebody recombination proceeds via successive pairwise interactions. We expect the underlying physical picture to be applicable not only to the narrow $s$ wave resonances, but also to resonances in other partial waves, and not only at ultracold temperatures, but also at higher temperatures. It points to some future directions towards a more complete understanding of threebody physics in general and molecule formation in particular. [Preview Abstract] 

D1.00156: ATOMIC, MOLECULAR AND CHARGED PARTICLE COLLISIONS 

D1.00157: Separating sequential from concerted threebody fragmentation of molecules T. Severt, Jyoti Rajput, Ben Berry, Bethany Jochim, Peyman Feizollah, Kanaka Raju P., M. Zohrabi, U. Ablikim, Farzaneh Zaiee, Balram Kaderiya, D. Rolles, A. Rudenko, K. D. Carnes, B. D. Esry, I. BenItzhak The ability to disentangle threebody sequential from concerted fragmentation events has been a longstanding endeavor when imaging molecular dynamics. Here, we study the multiphoton dissociative ionization of OCS to O$^+ + $ C$^+ + $ S$^+$ via two sequential pathways involving either a metastable CS$^{2+}$ or CO$^{2+}$ molecule. To separate sequential events, we transform to the centerofmass frame of the rotating intermediate dication and compute the angle $\gamma$ between the C$^+$ and the dication's center of mass momenta. When the lifetime of the intermediate fragment is much larger than its rotational period, the $N(\gamma)$ distribution is expected to be uniform, which can be used to extract sequential events. Improving on previously proposed methods, we exploit the uniformity of $N(\gamma)$ allowing events hidden by concerted breakup to be retrieved, leading to the separation of both sequential channels from the concerted events. Therefore, any spectra can be created showing either the sequentialonly or concertedonly contribution to the breakup. [Preview Abstract] 

D1.00158: The generalized Onsager model and DSMC simulations of highspeed rotating flows with product and waste baffles Dr. Sahadev Pradhan The generalized Onsager model for the radial boundary layer and of the generalized CarrierMaslen model for the axial boundary layer in a highspeed rotating cylinder ((S. Pradhan {\&} V. Kumaran, J. Fluid Mech., 2011, vol. 686, pp. 109159); (V. Kumaran {\&} S. Pradhan, J. Fluid Mech., 2014, vol. 753, pp. 307359)), are extended to a multiply connected domain, created by the product and waste baffles. For a single component gas, the analytical solutions are obtained for the sixthorder generalized Onsager equations for the master potential, and for the fourthorder generalized CarrierMaslen equation for the velocity potential. In both cases, the equations are linearized in the perturbation to the base flow, which is a solidbody rotation. An explicit expression for the baffle stream function is obtained using the boundary layer solutions. These solutions are compared with direct simulation Monte Carlo (DSMC) simulations and found excellent agreement between the analysis and simulations, to within 15{\%}, provided the wallslip in both the flow velocity and temperature are incorporated in the analytical solutions. [Preview Abstract] 

D1.00159: Electroninteracting WIMPs: Can dark matter scattering on electrons explain the DAMA modulation signal? Benjamin Roberts, Vladimir Dzuba, Victor Flambaum, Gleb Gribakin, Maxim Pospelov, Yevgeny Standik Atoms can become ionised during the scattering of a slow, heavy particle off a bound electron. Such an interaction involving leptophilic WIMP dark matter is a potential explanation for the anomalous $9\sigma$ annual modulation in the DAMA direct detection experiment. We show that due to nonanalytic, cusplike behavior of Coulomb functions close to the nucleus leads to an effective atomic structure enhancement. Crucially, we also show that electron relativistic effects are important. With this in mind, we perform highaccuracy relativistic calculations of atomic ionisation. We scan the parameter space: the DM mass, the mediator mass, and the effective coupling strength, to determine if there is any region that could potentially explain the DAMA signal. While we find that the modulation fraction of all events with energy deposition above 2 keV in NaI can be quite significant, reaching 50\%, the relevant parts of the parameter space are excluded by the XENON10 and XENON100 experiments.\\ B. M. Roberts, V. V. Flambaum, and G. F. Gribakin, Phys. Rev. Lett. 116, 023201 (2016).\\ B. M. Roberts, V. A. Dzuba, V. V. Flambaum, M. Pospelov, and Y. V. Stadnik, Phys. Rev. D 93 115037 (2016). [Preview Abstract] 

D1.00160: A simple method to obtain very accurate whole atom Compton profiles from photon scattering doubly differential cross sections in relativistic regimes Larry LaJohn Compton profiles (CP) are used in many ways such as for assessing the bonding properties of molecules and solids including semiconductors. The simplest approach to obtain a CP from doubly differential cross sections (DDCS) is to use the nonrelativistic (nr) impulse approximation (IA) expression DDCS$=$KJ where K is the kinematic factor and J is the CP. A relativistic version of this expression to be referred to as RKJ, an approximation to the full relativistic IA expression is used for relativistic regimes, but it does not give accurate results for the inner and middle shells of moderate to heavy atoms. For example the RKJ error ranges from 3{\%} (Z$=$30) to about 28{\%} (Z$=$92) for the Kshell and about 3{\%} (Z$=$50) to 17{\%} (Z$=$92) for the 2p shell and is at 6{\%} for 3d (Z$=$92). In the present work, expressions from nonrelativistic hydrogenlike wavefunctions (with a relativistic QED K) to correct RKJ beyond the Kshell to L and M shells were derived such that relativistic contributions as well as screening effects largely cancel for any regime of energy angle and Z. As a result the RKJ error is reduced to less than 2{\%} over 99{\%} of the momentum distribution range of any subshell CP. [Preview Abstract] 

D1.00161: Theoretical study of the D$^{}$ + H$_2$ $\rightarrow$ H$^{}$ + HD reaction at low energies Chi Hong Yuen, Mehdi Ayouz, Viatcheslav Kokoouline The rearrangement reaction D$^{}$ + H$_2$ $\rightarrow$ H$^{}$ + HD has been studied in a recent experimental work at low temperatures (10,19,and 23K) [1]. An upper limit of about 10$^{18}$~cm$^3$/s for the rate coefficient is obtained. A fullyquantum reactive scattering calculation of the rate coefficient is performed using the hyperspherical coordinates and the potential energy surface in Ref. [2]. Eigenchannel Rmatrix approach with modified slow variable discretization [3] is used to represent continuum wave functions of the system to obtain the scattering matrix describing the scattering from the initial rovibrational channel of the H$_2$+D$^$ into possible channels of H$^{}$ + HD. At low collision energies between H$_2$ in the ground state and D$^$, only three rotational channels of HD($v,j$) + H$^$ are open for the reaction with $v=0$ and $j=0,1,2$. Formulas for the cross section and rate coefficient for reactive scattering in hyperspherical coordinates are derived. Preliminary results for the rate coefficient of the D$^{}$ + H$_2$ $\rightarrow$ H$^{}$ + HD reaction is obtained. [1]Endres \textit{et al}, in press, PRA (2017) [2] Ayouz \textit{et al}, JCP \textbf{132}, 19 (2010) [3] Yuen and Kokoouline, EPJD, \textbf{71},19 (2017) [Preview Abstract] 

D1.00162: Theoretical Studies of Dissociative Recombination of Electrons with SH$^+$ Ions D. O. Kashinski, O. E. Di Nallo, A. P. Hickman, J. Zs. Mezei, F. Colboc, I. F. Schneider, K. Chakrabarti, D. Talbi We are investigating the dissociative recombination (DR) of electrons with the molecular ion SH$^+$, i.e. $e^ + \mathrm{SH}^+ \rightarrow \mathrm{S + H}$. SH$^+$ is found in the interstellar medium (ISM), and little is known concerning its chemistry. Understanding the role of DR of electrons with SH$^+$ will lead to more accurate astrophysical models. Large activespace multireference configuration interaction (MRCI) electronic structure calculations were performed using the GAMESS code to obtain ground and excited $^2\Pi$ state potential energy curves (PECs) for several values of SH separation. Coreexcited Rydberg states have proven to be of huge importance. The block diagonalization method was used to disentangle interacting states and form a diabatic representation of the PECs. Currently we are performing dynamics calculations using Multichannel Quantum Defect Theory (MQDT) to obtain DR rates. The status of the work will be presented at the conference. [Preview Abstract] 

D1.00163: Nonperturbative distortedwave approach for asymptotic solutions of coupledchannel scattering problems D. Shu, I. Simbotin, R. C\^ot\'e We developed and implemented a numerical method using distorted waves for coupledchannel scattering problems. Solutions of the full problem are expressed as ${\bf F=A}(r)f+{\bf B}(r)g$, where $f$ and $g$ are solutions of the singlechannel problem including the full diagonal potential. The `unperturbed' distortedwaves $f$ and $g$ are obtained using our newly developed scheme for Milne's phaseamplitude method. The differential equations for ${\bf A}(r)$ and ${\bf B}(r)$ are recast in the new variable $x=1/r$, and are solved using a spectral integration method based on Chebyshev polynomials. Our approach takes advantage of the fact that Milne's phase and amplitude, as well as ${\bf A}(r)$ and $\textbf{B}(r)$, are slowly varying functions. Moreover, the simple change of variable $x=1/r$ allows one to take fully into account the infinite tail of the potentials in a very efficient way. [Preview Abstract] 

D1.00164: Xray emission measurements following charge exchange between O$^{8+}$ and Kr R. T. Zhang, C. C. Havener, D. G. Seely, V. M. Andrianarijaona, M. Fogle, P. C. Stancil, D. Wulf, D. McCammon Lyman spectra and lineratios for soft Xray following charge exchange between O$^{8+}$ and Kr were measured using a beamgas technique and a high resolution microcalorimeter Xray detector for the collision velocities from 293 km/s to 1256 km/s. Ly$\alpha$, Ly$\beta$, Ly$\gamma$, Ly$\delta$, Ly$\varepsilon$ lines of O$^{7+}$ ion were identified, as well as minor transition lines from O$^{6+}$. Our observed line ratios are compared to a single charge exchange model, specifically with theoretical calculations for O$^{8+}$  H. Good agreement is found for the line ratio from the dominant $n = 5$ capture states, with direct capture and cascade having an important influence on the line ratio for the $n = 4$ states. Moreover, for velocities lower than 600 km$/$s, Xray emission following autoionizing double capture results in Ly$\alpha$ and Ly$\beta$ enhancement, the former leads to the Ly$\varepsilon$/Ly$\alpha$ line ratios significantly smaller than theoretical calculations, the latter leads to the Ly$\beta$/Ly$\alpha$ line ratios larger than theory. The apparatus is being modified to perform measurements with H using a mergedbeam technique. [Preview Abstract] 

D1.00165: Stable thermophoretic trapping of generic particles at low pressures Long Fung Frankie Fung We demonstrate levitation and threedimensionally stable trapping of a wide variety of particles in medium vacuum through thermophoresis. Typical sizes of the trapped particles are between 10 $\mu m$ and 1 mm; air pressure is between 1 and 10 Torr. We describe the experimental setup used to produce the temperature gradient, as well as our procedure for introducing particles into the experimental setup. To determine the levitation force and test various theoretical models, we examine the levitation heights of spherical polyethylene spheres under various conditions. A good agreement with two theoretical models is concluded. Our system offers a platform to discover various thermophoretic phenomena and to simulate dynamics of interacting manybody systems in a microgravity environment. [Preview Abstract] 

D1.00166: Control and analysis of atomic breakup dynamics Nishshanka Aruma Handi DeSilva, Sachin Sharma, Daniel Fischer Understanding the dynamics of coupled fewbody systems is one of the most fundamental and challenging tasks in physics. The theoretical obstacle is solving the equations of motion, which is analytically not possible for more than twobodies. Therefore, the advancement of our knowledge on few and many body phenomena relies on the comparison of theoretical predictions with detailed experimental observations. The experimental study of fewbody dynamics requires, first, the control of the system in a wellcharacterized initial state and second, the analysis of the evolution of the system after an external interaction. In this poster, we report on an experiment, where laser cooling and manipulation techniques are employed for controlling atomic fewbody system (Lithium atoms) by exciting, trapping, and cooling the atoms even to degeneracy. For the analysis, a 'reaction microscope' is used to coincidently measure the momenta of atomic fragments after ionization. This is achieved in a MOTReMI, the unique implementation of a magnetooptical trap in a reaction microscope. There are fundamental and diverse questions, to be answered in the planned experiments, among them: How ionization dynamics and timing depend on electronic correlation and relative helicity of field and atom? How does the environment of the atoms influence their ionization? How to image the correlated wave function of atomic samples in dependence on the particle number, interaction type and strength? [Preview Abstract] 
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