Bulletin of the American Physical Society
46th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 60, Number 7
Monday–Friday, June 8–12, 2015; Columbus, Ohio
Session D1: Poster Session I (4:00 pm  6:00 pm) 
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Sponsoring Units: APS Room: Convention Center Battelle South 

D1.00001: QUANTUM GASES IN LOW DIMENSIONS 

D1.00002: Atom and Electron Pump Based on Oscillating Wells: Classical versus Quantum features Joshua Garner, Kevin Ruppert, Kunal Das The transport dynamics of ultracold atoms in quasi onedimensional (1D) waveguides share much in common with that of electrons and holes in nanowires. In the latter system, biasless transport by timevarying potential, commonly called quantum pumping, has been much researched theoretically as a mechanism that can provide significant control over the current. With scant experimental success, ultracold atoms provide a promising alternate for exploring quantum pumps. Prior studies of quantum pumps have generally focused on using potential barriers as the pump elements. In this study, we undertake a first detailed study of the scattering dynamics involved in using quantum wells to drive the pumping. Specifically, we do a comparative study using quantum, classical and semiclassical picture in a common wavepacket approach that also allows direct comparison of quantum versus classical features. Notably, a static well, unlike a barrier, does not reflect; but oscillating ones do even in the classical limit, and moreover, particles can be trapped in wells indefinitely. Such features lead to distinctive features for wellbased pumps that can have both practical and fundamental physics implications. Our study is done in the context of several different pump configurations. [Preview Abstract] 

D1.00003: Implementation of an adjustablelength cavity/BEC system for multimode cQED Alexander Papageorge, Alicia Kollar, Benjamin Lev Investigations of manybody physics in an AMO context often employ a static optical lattice to create a periodic potential. Such systems, while capable of exploring, e.g., the Hubbard model, lack the fully emergent crystalline order found in solid state systems whose stiffness is not imposed externally, but arises dynamically. Our new multimode cavity QED experiment introduces fully emergent and compliant optical lattices to the ultracold atom toolbox and provides new avenues to explore beyond meanfield physics. Quantum liquid crystals, spin glasses, and associative memory may arise due to the oscillatory, frustrated, and tunablerange interactions mediated by the optical cavity modes. We report the demonstration of an apparatus capable of producing a $^{87}$Rb BEC localized in the center of a degenerate multimode Fabry{Per\'{o}t} cavity [1]. One of the cavity's mirrors is affixed to a nanopositioning stage, allowing for considerable length deviations ($\pm$1~mm) from the nominal confocal separation of 1~cm. We observe dispersive lightmatter interaction in a variety of cavity configurations. We will discuss progress toward future experiments. \\[4pt] [1] A. J. {Koll\'{a}r}, A. T. Papageorge, K. Baumann, M. A. Armen, and B. L. Lev, arXiv:1411.3069 (2014). [Preview Abstract] 

D1.00004: Preparing and probing manybody correlated systems in a Quantum Gas Microscope by engineering arbitrary landscape potentials Matthew Rispoli, Alexander Lukin, Ruichao Ma, Philipp Preiss, M. Eric Tai, Rajibul Islam, Markus Greiner Ultracold atoms in optical lattices provide a versatile tool box for observing the emergence of strongly correlated physics in quantum systems. Dynamic control of optical potentials on the singlesite level allows us to prepare and probe manybody quantum states through local Hamiltonian engineering. We achieve these high precision levels of optical control through spatial light modulation with a DMD (digital micromirror device). This allows for both arbitrary beam shaping and aberration compensation in our imaging system to produce high fidelity optical potentials. We use these techniques to control state initialization, Hamiltonian dynamics, and measurement in experiments investigating lowdimensional manybody physics  from onedimensional correlated quantum walks to characterizing entanglement. [Preview Abstract] 

D1.00005: Towards measuring the transport properties of quantum mixtures in 1D rings Yanping Cai, Kevin Wright We are constructing a new ultracold $^6$Li$^7$Li experiment optimized for studying interacting quantum mixtures both in low dimensions and in multiplyconnected geometries. Starting from a dualspecies 2DMOT for 6Li and 7Li, we will capture and cool both species to degeneracy and load them (independently or as a mixture) into precisely engineered optical dipole traps. We have developed techniques for trapping atoms in configurations (e.g. rotating 1D ring lattices) where unusual quantum phases have been predicted to appear. We plan to make detailed measurements of the anomalous mass and spin transport properties that are the key signatures of some of these quantum phases. [Preview Abstract] 

D1.00006: Phase diagrams for massimbalanced fewbody systems in one dimension Connor Morehead, Nirav Mehta We have calculated the atomdimer and atomtrimer scattering lengths, as well as the universal trimer and tetramer binding energies for mixtures of heavy (H) and light (L) particles in one dimension. All universal observables are presented as functions of the scattering length ratio ($a_{HH}/a_{HL}$) and the mass ratio ($m_H/m_L$). We present phase diagrams for the HHL and HHHL system indicating the number of universal bound states, the sign of the atomdimer and atomtrimer scattering lengths, and the positions of the atomdimer and atomtrimer zeroenergy scattering resonances. [Preview Abstract] 

D1.00007: Characterizing spincharge separation using Bragg spectroscopy Seth T. Coleman, TsungLin Yang, Randall G. Hulet One dimensional systems of fermions are predicted by Luttinger liquid theory to have different dispersion relations for the spin and charge excitations. Spincharge separation has been previously seen in quantum wire tunneling experiments.\footnote{O. M. Auslaender et al., Science \textbf{308}, 88 (2005).}\textsuperscript{,}\footnote{Y. Jompol et al., Science \textbf{325}, 597 (2009).} Ultracold atoms, however, provide a highly tunable and precise system to directly observe this phenomenon. We propose to realize such a system with fermionic $^{6}$Li in a 2D optical lattice, measuring the spin and charge dispersion relations using Bragg spectroscopy.\footnote{S. Hoinka et al., Phys. Rev. Lett. \textbf{109}, 050403 (2012).} Bragg spectroscopy offers the ability to probe a large region of the excitation spectrum, since it does not change the internal state of the atoms and total momentum transfer is adjustable. By exploiting the tunability of interactions, via a Feshbach resonance, and the adjustability of the optical potential, we will characterize spincharge separation under a wide range of experimental parameters. [Preview Abstract] 

D1.00008: Onedimensional Fermi gas with a single impurity in a harmonic trap: Perturbative description of the upper branch Seyed Ebrahim Gharashi, X.Y. Yin, Yangqian Yan, D. Blume The transition from ``few to many'' has recently been probed experimentally in an ultracold harmonically confined onedimensional lithium gas, in which a single impurity atom interacts with a background gas consisting of one, two, or more identical fermions [A. N. Wenz {\em{et al.}}, Science {\bf{342}}, 457 (2013)]. For repulsive interactions between the background or majority atoms and the impurity, the interaction energy for relatively moderate system sizes was analyzed and found to converge toward the corresponding expression for an infinitely large Fermi gas. Motivated by these experimental results, we apply perturbative techniques to determine the interaction energy for weak and strong coupling strengths and derive approximate descriptions for the interaction energy for repulsive interactions with varying strength between the impurity and the majority atoms and any number of majority atoms. [Preview Abstract] 

D1.00009: TRANSPORT AND OUTOFEQUILIBRIUM DYNAMICS WITH ULTRACOLD ATOMS 

D1.00010: Correlated Quantum Dynamics of a Single Atom Collisionally Coupled to an Ultracold Finite Bosonic Ensemble Sven Kr\"onke, Johannes Kn\"orzer, Peter Schmelcher We explore the correlated quantum dynamics of a single atom with a spatiotemporally localized coupling to a finite bosonic ensemble [{\it arXiv:1410.8676}]. The single atom is initially prepared in a coherent state of low energy and oscillates in a harmonic trap. An ensemble of $N_A$ interacting bosons is held in a displaced trap such that it is periodically penetrated by the single atom. The nonequilibrium quantum dynamics of the total system is simulated by means of an {\it abinitio} method. Here, we focus on characterizing the impact of the peculiar interspecies coupling and the thereby induced interspecies correlations on the subsystem states: At instants of not too imbalanced excess energy distribution among the subsystems, interspecies correlations prove to be significant. A phasespace analysis for the single atom reveals that these correlations manifests themselves in short phases of strong deviations from a coherent state. In the bosonic ensemble, the single atom mainly induces singlet and delayed doublet excitations, for which we offer analytical insights with a stroboscopic timedependent perturbation theory approach. When increasing the ensemble size, its maximal dynamical quantum depletion is shown to decrease faster than $1/N_A$ for a fixed excess energy. [Preview Abstract] 

D1.00011: Thermalization vs. Localization in the Disordered Hubbard Model William Morong, Wenchao Xu, William McGehee, Brian DeMarco Using ultracold 40K fermions trapped in a disordered optical lattice, we observe the presence of a stronglyinteracting, localized state in a realization of the disordered FermiHubbard model. Through measurements of centerofmass velocity after an applied impulse, we show that this localized state persists to nonzero temperature, in contrast with longstanding expectations but in agreement with the general predictions of recent manybody localization (MBL) models. We propose further experiments to clarify the presence of MBL states in a closed, stronglyinteracting 3D system, and more generally investigate the thermalization or lack thereof under these conditions. [Preview Abstract] 

D1.00012: Solution of the Fr\"ohlich polaron problem at intermediate couplings Fabian Grusdt, Yulia E. Shchadilova, Alexey N. Rubtsov, Eugene Demler We develop a renormalization group approach for analyzing Fr\"ohlich polarons and apply it to a problem of impurity atoms immersed in a BoseEinstein condensate (BEC) of ultra cold atoms. Polaron energies obtained by our method are in excellent agreement with recent diagrammatic Monte Carlo calculations [1] for a wide range of interaction strengths. We show analytically that the energy of the Fr\"ohlich polaron in a BEC is logarithmically UV divergent, and present a regularization scheme. This allows us to make predictions for the polaron energy, which can be tested in future experiments. Furthermore we calculate the effective mass of polarons and find a smooth crossover from weak to strong coupling regimes. Our method can be generalized to nonequilibrium polaron problems.\\[4pt] [1] Vlietinck et al., arXiv:1406.6506\\[0pt] [2] Grusdt et al.,arXiv:1410.2203\\[0pt] [3] Shchadilova et al.,arXiv:1410.5691 [Preview Abstract] 

D1.00013: Measurementinduced Localization in an Ultracold Lattice Gas Srivatsan Chakram, Yogesh Sharad Patil, Mukund Vengalattore We demonstrate the control of quantum tunneling in an ultracold lattice gas by the measurement backaction imposed by an imaging process. The backaction induced by position measurements modifies the coherent quantum tunneling of atoms within the lattice. We vary the rate at which atoms are imaged, and observe the crossover from the weak measurement regime, where the measurement has a negligible effect on coherent dynamics, to the strong measurement regime, where measurementinduced localization leads to a dramatic suppression of tunneling  a manifestation of the Quantum Zeno effect [1]. Our technique demonstrates a powerful tool for the control of an interacting manybody quantum system via spatially resolved measurement backaction. We also shed light on the implications of quantum measurement on the coherent evolution of a mesoscopic quantum system.\\[4pt] [1] Y. S. Patil \em etal.\em\ arXiv: 1411.2678 [Preview Abstract] 

D1.00014: Decoherence and tunneling of an interacting gas James Anglin, Luis RicoPerez, Daniel Wohlfarth In quasisteady escape of a confined interacting gas by quantum tunneling, collisional decoherence can reduce the escape rate through a manybody version of the CaldeiraLeggett effect. This explains why classical fluids fail to tunnel, even though they are composed of particles small enough to be quantum mechanical. We compute this effect in the MaxwellBoltzmann regime by deriving a quantum generalization of the Boltzmann equation. We show that decoherence effectively makes tunneling of an interacting gas into an irreversible process: a uniquely quantum mechanical form of throttling. The rate of entropy production in tunneling is related in the semiclassical limit to the imaginary part of the singleparticle action. [Preview Abstract] 

D1.00015: An Effective Collision Rate Model for Atomtronic Devices Cameron J.E. Straatsma, Weng W. Chow, Dana Z. Anderson We demonstrate application of a model, previously developed for the detailed study of quantum electronic systems [1], to atomtronic devices utilizing finite temperature Bosecondensed gases. The numerical approach is based on the relaxation rate approximation where collisions effectively drive the system towards a dynamical (nonthermal) equilibrium distribution. This approach allows parametric studies involving time scales that cover both the rapid population dynamics relevant to nonequilibrium state evolution, as well as the much longer time durations typical of steadystate device operation. The model is demonstrated by studying the evolution of a Bosecondensed gas in the presence of atom injection and extraction in a doublewell potential. In this configuration phaselocking between condensates in each well of the potential is readily observed, and its influence on the evolution of the system is studied.\\[4pt] [1] W. W. Chow and S. W. Koch, IEEE J. Quantum Elec., \textbf{41}, 495 (2005) [Preview Abstract] 

D1.00016: NonEquilibrium Dynamics of Fermi Gases Near A Scattering Resonance S. Trotzky, C. Luciuk, S. Smale, S. Beattie, E. Taylor, T. Enss, Shizhong Zhang, J. H. Thywissen We present recent dynamic measurements of fermionic potassium ($^{40}$K) near FanoFeshbach scattering resonances. In our experiments, we start with a weakly or noninteracting Fermi gas and initiate strong interactions on a timescale that is fast compared to the equilibration mechanisms in the system quasiinstantaneous quench. Equally fast measurements allow us to follow the nonequilibrium manybody dynamics. First, we discuss timeresolved radiofrequency (rf) spectroscopy, and its use to probe the evolution of the shortrange part of the manybody wave function  i.e., the contact. Second, we discuss spinecho measurements that reveal the nature of transverse spin transport. Most recently, we have studied a Fermi gas with repulsive interactions in the metastable upper branch of the energy spectrum near a swave scattering resonance. [Preview Abstract] 

D1.00017: Positive and negative quenches induced excitation dynamics for ultracold bosons in onedimensional lattices Simeon Mistakidis, Lushuai Cao, Peter Schmelcher The correlated nonequilibrium dynamics of fewboson systems in onedimensional finite lattices is investigated. Focusing on the lowlying modes of the finite lattice we observe the emergence of densitywave tunneling, breathing and cradlelike processes. In particular, the tunneling induced by the quench leads to a global densitywave oscillation. The resulting breathing and cradle modes are inherent to the local intrawell dynamics and related to excitedband states. Positive interaction quenches couple the densitywave and the cradle modes allowing for resonance phenomena [1]. Moreover, the cradle mode is associated with the initial delocalization and following a negative interaction quench can be excited for setups with filling larger than unity. For subunit fillings it can be accessed with the aid of a negative quench of the lattice depth [2]. Finally, our results shed light to possible controlling schemes for the cradle and the breathing modes. The evolution of the system is obtained numerically using the abinitio multilayer multiconfiguration timedependent Hartree method for bosons.\\[4pt] [1] S. I. Mistakidis, L. Cao, and P. Schmelcher, J. Phys. B: At. Mol. Opt. Phys. 47 225303 (2014). \\[0pt] [2] S. I. Mistakidis, L. Cao, and P. Schmelcher, arXiv preprint arXiv:1412.1375 (2014). [Preview Abstract] 

D1.00018: SPINOR GASES AND MAGNETIC PHENOMENA 

D1.00019: Dynamics of a spinor atomSQUID Ranchu Mathew, Eite Tiesinga Over the past few years, there has been a concerted effort at NIST studying the atomic analogue of a superconducting quantum interference device (SQUID). The atomSQUID consists of a BoseEinstein condensate in a ring trap with a rotating external weak link. The phenomena of persistent current and hysteresis have been experimentally observed in this system. We investigate the effect of the spin degree of freedom on the stability of persistentcurrent states and hysteresis in a spin1 atomSQUID. Interatomic interactions now allow coherent oscillations between the spin projections while conserving total magnetisation. We study the meanfield states of a spin1 system within a twomode approximation, where the two spatial modes are planewave modes with winding number zero and one. Furthermore, we calculate the Bogoliubov spectrum to study the combined effect of an external magnetic field and rotation rate on the stability and coupling of the spin and mass current. [Preview Abstract] 

D1.00020: Decay of an isolated monopole into a Dirac monopole Konstantin Tiurev, Emmi Ruokokoski, Harri M\"akel\"a, Mikko M\"ott\"onen, David Hall Recently, we experimentally discovered topological point defects in the polar phase of spin1 BoseEinstein condensates of $^{87}$Rb atoms.\footnote{M. W. Ray, E. Ruokokoski, K. Tiurev, M. M\"ott\"onen, and D. S. Hall. Observation of isolated monopoles in a quantum field. Unpublished, 2015} We numerically study the detailed decay dynamics of these isolated monopoles in experimentally realizable conditions. We find that the monopole decays by a dynamical quantum phase transition away from the polar phase. The resulting ferromagnetic order parameter is observed to exhibit a Dirac monopole in its synthetic magnetic field.\footnote{M. W. Ray, E. Ruokokoski, S. Kandel, M. M\"ott\"onen, and D. S. Hall. Observation of Dirac monopoles in a synthetic magnetic field. Nature, 505:657660, 2014.} We furthermore show that the spinspin interaction, quadratic Zeeman term and the threebody recombination seem to have no effect on the qualitative decay dynamics. These studies set the stage for the dynamics of topological point defects in quantum fields. Finding ways to extend the lifetime of the defect and thereafter to study the dynamics of multiple interacting point defects remains a future challenge. [Preview Abstract] 

D1.00021: Quantum Phase Transitions and Adiabatic Control of Ferromagnetic Spin1 BEC Thai Hoang, Martin Anquez, Bryce Robbins, Bharath Madhusudhana, Matthew Boguslawski, Michael Chapman The adiabatic theorem, which states that a quantum system can remain in its instantaneous eigenstate under slow temporal changes to the Hamiltonian, was formulated almost 100 years ago by Born and Fock. This phenomenon relies on the existence of an energy gap between neighboring eigenstates of the quantum system and has proved to be a powerful tool in realizing novel quantum computation algorithms. Furthermore, the energy gap between the ground and first excited state plays a crucial role in understanding the dynamics of quantum phase transitions and the KibbleZurek mechanism. A spin1 BoseEinstein condensate (BEC) features a wellcharacterized and controllable Hamiltonian, providing a unique framework for investigating quantum phase transition phenomena. A massive entanglement Dicke state can also be generated by exploiting the nonzero energy gap at the quantum critical point (QCP) and adiabatic quantum phase transition of the ground state (highest eigenstate) in a ferromagnetic (antiferromagnetic) condensate. Here, we experimentally investigate the energy gap and adiabaticity in a ferromagnetic BEC and compare our results to quantum simulations. [Preview Abstract] 

D1.00022: KibbleZurek Mechanism in a Spin1 Ferromagnetic BEC Martin Anquez, Bryce Robbins, H.M. Bharath, Matthew Boguslawski, Thai Hoang, Michael Chapman A ferromagnetic spin1 $^{87}$Rb BEC exhibits a secondorder gapless quantum phase transition due to the competition between magnetic and collisional spin interaction energies. In such a system, we expect to observe universal KibbleZurek powerlaw scaling of the excitations for slow quenches through the critical point. In spatially extended systems, the KibbleZurek mechanism is manifest in topological defects. In our small spin condensates, the excitations appear in the temporal evolution of the spin populations.\footnote{ Damski, B., \& Zurek, W. H. (2007). Dynamics of a Quantum Phase Transition in a Ferromagnetic BoseEinstein Condensate. Physical Review Letters, 99(13), 130402.} In this poster, we present our experimental investigation of the spin excitations as a function of the quench speed when the system is driven from the polar to ferromagnetic phase. Our results are quantitatively compared with quantum simulations. [Preview Abstract] 

D1.00023: Formation and dynamics of antiferromagnetic correlations using ultracold fermions Michael Messer, Daniel Greif, Gregor Jotzu, Frederik G\"{o}rg, R\'{e}mi Desbuquois, Tilman Esslinger Ultracold fermions in optical lattices are an ideal toolbox for studying quantum magnetism in the Hubbard model. In this model many questions on the lowtemperature phase diagram still remain open, both for simple cubic and square configurations, as well as for more complex lattice geometries. Besides a highly controlled approach to studying the thermodynamic properties cold atoms can also give insight into the dynamic properties of the system. In our experiment we load a twocomponent, repulsively interacting fermionic quantum gas into a tunablegeometry optical lattice. We observe antiferromagnetic spin correlations on neighboring sites in both isotropic 3D cubic and 2D square lattices for very low temperatures. In addition we study the strength of the spin correlations in more complex lattice geometries, such as honeycomb, 1Ddimerized and spinladder lattice configurations. Furthermore, we demonstrate first experimental results on the dynamics of spin correlations by measuring their characteristic formation time. [Preview Abstract] 

D1.00024: ULTRACOLD COLLISIONS AND PHTOASSOCIATION PROCESSES 

D1.00025: Preparation for Acceleration and Deceleration of Cold Rydberg Atoms in the Field of a Charged Wire Anne Goodsell, Poomirat Nawarat, W. Colleen Harper We are preparing for experiments using cold Rydberg atoms in linear Stark states. We cool and launch Rb atoms at 212 m/s toward a charged wire with a cylindricallysymmetric electric field. The cold cloud will be illuminated in midflight to promote atoms into the desired Rydberg state (e.g. $n$ = 3340). With a threephoton sequence we will access $nf$ states and the nearby manifolds (parabolic quantum number 0 $\le n_1\le$ ($n4$)) with linear Stark shifts. This requires specific detuning of the the excitation laser, which allows us to selectively compare states that are strongly accelerated to states that are strongly decelerated. With the wire at +10 V, atoms launched at 10 m/s, and excitation near 750 $\mu$m from the wire, the displacement during the Rydberg lifetime (e.g. $n$ =35, $\tau$ = 30 $\mu$s) will be ~200300 $\mu$m farther for extreme attracted states ($n_1$ = 0) than for extreme repelled states ($n_1$ = 31). Detection will occur by spatiallydependent field ionization. Observations of atoms with zero angular momentum around the wire can be extended to atoms with nonzero angular momentum and also to study the dynamics of Rydberg atoms with a quadratic Stark shift, building on previous work with groundstate atoms [1]. \\[4pt] [1] PRL 104, 133002 (2010). [Preview Abstract] 

D1.00026: Electron Forced Evaporative Cooling in Ultracold Plasmas Craig Witte, Jacob Roberts Ultracold plasmas (UCPs) are formed by photoionizing a collection of laser cooled atoms. Once formed, these plasmas expand, cooling over the course of their expansion. In theory, further cooling should be obtainable by forcibly inducing electron evaporation through applying DC electric fields to extract electrons. However, for many UCP parameters, UCP electrons are not fully thermalized until very late in the expansion. This creates complications in analyzing the UCP. This problem can be remedied by creating the ultracold plasma at substantially lower initial temperatures since thermalization rates increase with decreasing temperature. Unfortunately, traditional models of UCP dynamics tend to break down in cases of substantial nonneutrality when used in the limit of zero temperature. We have developed a theoretical model that calculates potential depth and expansion dynamics of nonneutral UCPs in the limit of zero temperature. Such a model will allow us to quantify the degree of cooling obtained by evaporation as measured experimentally. [Preview Abstract] 

D1.00027: Production of Ultracold Molecules with Chirped NanosecondTimescale Pulses Jennifer Carini, Shimshon Kallush, Ronnie Kosloff, Phillip Gould We describe quantum simulations of ultracold $^{87}$Rb$_{2}$ molecule formation using photoassociation with nanosecondtimescale pulses of frequency chirped light. In particular, we compare the case of a linear chirp to one where the frequency evolution is optimized by local control of the phase, and find that local control can provide a significant enhancement. The resulting optimal frequency evolution corresponds to a rapid jump from the photoassociation absorption resonance to a downward transition to the target state, a bound level of the lowest triplet state. We also consider the case of two frequencies and investigate interference effects. The assumed chirp parameters should be achievable with nanosecond pulse shaping techniques and are predicted to provide a significant enhancement over recent experiments [PRA 87, 011401(R) (2013)] with linear chirps. This work is supported by DOE and BSF. [Preview Abstract] 

D1.00028: Production and alloptical deceleration of molecular beams Gary Chen, Andrew Jayich, Xueping Long, Anthony Ransford, Wesley Campbell Ultracold molecules open up new opportunities in many areas of study, including manybody physics, quantum chemistry, quantum information, and precision measurements. Current methods cannot easily address the spontaneous decay of molecules into dark states without an amalgam of repump lasers. We present an alternative method to produce cold molecules. A cryogenic buffer gas beam (CBGB) is used to create an intense, slow, cold source of molecules. By using a CBGB for the production, we can quench vibrational modes that cannot be addressed with optical methods. This is then followed by an alloptical scheme using a single ultrafast laser to decelerate the molecules and a continuous wave laser to cool the species. We have started experiments with strontium monohydride (SrH), but the proposed method should be applicable to a wide range of molecular species. [Preview Abstract] 

D1.00029: UltralongRange Cs DState Rydberg Molecules Jin Yang, Margarita Reschke, John Furneaux, Donald Booth, James Shaffer Ultralongrange Rydberg molecules are interesting because they are formed by electron scattering of bound Rydberg electrons from ground state atoms found near an excited Rydberg atom. Because of their novel physical properties, such as kiloDebye permanent dipole moments and novel binding mechanism, they are receiving increasing interest. Here, we present our work on ultralongrange Cs Rydberg molecules correlating asymptotically to dstates. Through comparison with prior experimental results on Rb and Cs ultralongrange molecules, we explain how state mixing and the details of different scattering processes work to give distinctive properties to these molecules that depend on quantum state and atomic species. [Preview Abstract] 

D1.00030: Quantum dynamics of Li+HF$\to$LiF+H reaction at low temperatures N. Balakrishnan, Jisha Hazra We report a quantum dynamics study of the Li+HF$\to$LiF+H reaction at low temperatures of interest to cooling and trapping experiments. Contributions from nonzero partial waves are analyzed and results show narrow resonances in the energy dependence of the cross section that survive partial wave summation. Results obtained using two ab initio electronic potential energy surfaces for the LiHF system show strong sensitivity to the choice of the potential. In particular, small differences in the barrier heights of the two potential surfaces are found to dramatically influence the reaction cross sections at low energies. Comparison with recent measurements of the reaction cross section shows similar energy dependence in the threshold regime and an overall good agreement with experimental data compared to previous theoretical results. [Preview Abstract] 

D1.00031: Towards producing ultracold CaNa$^+$ molecular ions in the ground electronic state Marko Gacesa, John A. Montgomery, Harvey H. Michels, Robin C\^ot\'e We present a theoretical analysis of optical pathways for the formation of cold Ca($^1$S)Na$^+$($^1$S) molecular ions, based on accurate potential energy curves and transition dipole moments calculated using effectivecorepotential methods of quantum chemistry. In the proposed approach, starting from a mixture of trapped lasercooled Ca$^+$ ions immersed into an ultracold gas of Na atoms, the (NaCa)$^+$ are photoassociated in the excited $E ^{1}\Sigma^+$ electronic state, followed by spontaneous radiative charge transfer and emission through an intermediate state. We find the optimal formation pathway and report radiative chargeexchange cross sections and vibrational distributions of participating electronic states. [Preview Abstract] 

D1.00032: Ultracold threebody recombination and Efimov physics under partial confinement Jose P. D'Incao, Yujun Wang, Brett Esry We present a study of the ultracold threebody problem in the presence of harmonic confinement along one direction, resulting in a quasitwodimensional geometry. We solve the problem essentially exactly using a formalism based on democratic hyperspherical coordinates and incorporating the anisotropic effects due to the confinement. We explore the connection between the usual threedimensional Efimov physics (present for distances smaller than the confinement length) and the universal twodimensional threebody physics (present at larger distances). We calculate threebody recombination rates and determine possible effects due to the confinement and their implication for experiments in quasitwo dimensional ultracold quantum gases with strong interactions. This work is supported by AFOSRMURI. [Preview Abstract] 

D1.00033: Heteronuclear threebody parameter pinned down by multichannel spinor model Yujun Wang, Paul S. Julienne, Chris H. Greene Although a quantitative study of ultracold threebody collisions has been recently performed for homonuclear atomic systems [1], a similar theoretical study for heteronuclear ones has not been available. In this work we show progress in predicting Efimovlike threebody resonances using multichannel spinor models. In particular, we show that our calculations correctly predict the experimental observed isotope dependence of the atomdiatomic resonances in $^{87}$Rb$^{87}$Rb$^{40}$K and $^{87}$Rb$^{87}$Rb$^{41}$K systems [2,3] without fitting parameters. Our study demonstrates that with our simple spinor models, quantitative characterization of ultracold chemical processes for heteronuclear systems is in principle feasible. Application of our model to other heteronuclear alkalimetal systems is also discussed. \\[4pt] [1] Y. Wang and P. S. Julienne, Nature Phys. 10, 768 (2014).\\[0pt] [2] R. S. Bloom, {\it et al.}, Phys. Rev. Lett. 111, 105301 (2013).\\[0pt] [3] K. Kato, {\it et al.}, in preparation (2015). [Preview Abstract] 

D1.00034: Towards Photoassociation in 87RB BEC with raman lightinduced synthetic gauge fields David Blasing, Yong Chen We present our experimental studies of photoassociation in 87Rb BoseEinstein condensate (BEC) both without and with the presence of Raman lightinduced gauge fields. These gauge fields couple the three bare m\textunderscore f spins in the F$=$1 manifold of 87Rb, with the new eigenstates being superpositions of the bare m\textunderscore f states. Some photoassociation channels are allowed or forbidden depending the m\textunderscore f spin of the colliding atoms. We will report the progress in our measurements, with the goal of investigating the role of synthetic gauge fields on the photoassociation process. [Preview Abstract] 

D1.00035: Quantum Defect Theory for Ultracold StateResolved Chemistry Jisha Hazra, Brandon Ruzic, John Bohn, Balakrishnan Naduvalath We present a formalism for cold and ultracold atomdiatom chemical reactions that combines a quantum closecoupling method at shortrange with quantum defect theory at longrange. The method yields full statetostate rovibrationally resolved cross sections as in standard closecoupling (CC) calculations but at a considerably less computational expense. This hybrid approach exploits the simplicity of MQDT while treating the shortrange interaction explicitly using quantum CC calculations. The method, demonstrated for D+H$_2\to$ HD+H collisions with rovibrational quantum state resolution of the HD product, is shown to be accurate for a wide range of collision energies and initial conditions. The hybrid CCMQDT formalism may provide an alternative approach to full CC calculations for cold and ultracold reactions. [Preview Abstract] 

D1.00036: Fundamental Interactions for Atom Interferometry with Ultracold Quantum Gases in a Microgravity Environment Jose P. D'Incao, Jason R. Willians Precision atom interferometers (AI) in space are a key element for several applications of interest to NASA. Our proposal for participating in the Cold Atom Laboratory (CAL) onboard the International Space Station is dedicated to mitigating the leadingorder systematics expected to corrupt future highprecision AIbased measurements of fundamental physics in microgravity. One important focus of our proposal is to enhance initial state preparation for dualspecies AIs. Our proposed filtering scheme uses Feshbach molecular states to create highly correlated mixtures of heteronuclear atomic gases in both their position and momentum distributions. We will detail our filtering scheme along with the main factors that determine its efficiency. We also show that the atomic and molecular heating and loss rates can be mitigated at the unique temperature and density regimes accessible on CAL. This research is supported by the National Aeronautics and Space Administration. [Preview Abstract] 

D1.00037: COLD RYDBERG GASES AND PLASMAS 

D1.00038: Magic wavelengths for the 5s18s transition in rubidium Elizabeth Goldschmidt, David Norris, Silvio Koller, Robert Wyllie, Roger Brown, Trey Porto, Ulyana Safronova, Marianna Safronova Magic wavelengths, for which there is no differential ac Stark shift for the ground and excited state of the atom, allow trapping of excited Rydberg atoms without broadening the optical transition. This is an important tool for implementing quantum gates and other quantum information protocols with Rydberg atoms, and reliable theoretical methods to find such magic wavelengths are thus extremely useful. We use a highprecision allorder method to calculate magic wavelengths for the $5s18s$ transition of rubidium near the $18s6p$ resonances. We compare the calculation to experiment by measuring the light shift for atoms held in a crossed optical dipole trap with wavelength tuned around the $18s6p_{3/2}$ resonance at the experimentally convenient wavelength of 1064$~$nm. [Preview Abstract] 

D1.00039: SinglePhoton Switch Based on Rydberg Blockade Simon Baur, Daniel Tiarks, Gerhard Rempe, Stephan Duerr Alloptical switching is a technique in which a gate light pulse changes the transmission of a target light pulse without the detour via electronic signal processing. We take this to the quantum regime, where the incoming gate light pulse contains only one photon on average. The gate pulse is stored as a Rydberg excitation in an ultracold atomic gas using electromagnetically induced transparency. Rydberg blockade suppresses the transmission of the subsequent target pulse. Finally, the stored gate photon can be retrieved. A retrieved photon heralds successful storage. The corresponding postselected subensemble shows a relative transmission of 0.05. The singlephoton switch offers many interesting perspectives ranging from quantum communication to quantum information processing.$\\$ $\\$ [1] S. Baur et al. PRL 112, 073901 (2014) [Preview Abstract] 

D1.00040: Creation, Control, and Detection of Rydberg Excitations in Ultracold Strontium Joseph Whalen, Roger Ding, Francisco Camargo, Germano Woehl Junior, F. Barry Dunning, Thomas Killian We benchmark a new apparatus for studying Rydberg physics in ultracold gases by demonstrating the ability to create, control, and detect highlying excitations. Twophoton transitions via the narrow 5s5p $^{3}$P$_{j}$ intercombination line, unique to alkalineearthlike atoms, are used to create triplet 5s\textit{nl} Rydberg states with enhanced lifetimes that are inaccessible in alkali systems. These Rydberg excitations have strong, longrange dipolar interactions that can be tuned with principal quantum number and Rydberg fraction. To monitor $n$ and the number of Rydberg atoms created we employ pulsedfield ionization and a microchannel plate detector. This work serves as an important milestone toward realizing manybody phenomena such as roton physics, 3D solitons, supersolidity and longrange spin models. [Preview Abstract] 

D1.00041: Producing Quantum Degenerate Gases of Strontium Francisco Camargo, Roger Ding, Joseph Whalen, Germano Woehl, Barry Dunning, Thomas Killian We present our progress towards producing quantum degenerate gases of all four stable isotopes of strontium ($^{84}$Sr, $^{86}$Sr, $^{87}$Sr, $^{88}$Sr) and isotopic mixtures. We characterize the performance of our broadline (461 nm, 30.5 MHz), narrowline (689 nm, 7.5 kHz) magnetooptical traps, and examine evaporative cooling for all four isotopes. The new apparatus will be used to create and study tunable longrange interactions by dressing with stronglyinteracting Rydberg states. The ability to trap the four different isotopes allows a measure of control of these interactions through access to a range of attractive and repulsive interactions. Simultaneous trapping of different isotopes provides opportunities for novel laser cooling schemes for studying BoseBose and BoseFermi mixtures. [Preview Abstract] 

D1.00042: DualSpecies Ultracold Neutral Plasma Daniel Woodbury, Alex Erikson, Scott Bergeson We present the design and characterization of a dual species Ca/Yb 2D/3D MOT. This setup allows us to create a mixed calcium and ytterbium ultracold neutral plasma to study transport mechanisms in a strongly coupled environment. This system is an analogue to electronion transport, that is not readily understood in dense plasmas. We report on the creation and optimization of the dual species trap and preliminary results for separate calcium and ytterbium plasma. These results demonstrate a robust method for trapping a large number of atoms in the trap and creating a dualspecies plasma. [Preview Abstract] 

D1.00043: Enhanced Selective Field Ionization with Optical Dumping Vincent C. Gregoric, Thomas J. Carroll, Michael W. Noel Detection of Rydberg atoms by field ionization provides some degree of state identification due to the 1/$n^4$ scaling of the ionization threshold. However, some state information is lost when the atoms traverse avoided crossings during the ionization process. Here, we present an experimental method utilizing a ``dump pulse'' to detect dipoledipole interactions involving initial and final states which would otherwise be indistinguishable in a field ionization signal. [Preview Abstract] 

D1.00044: Lasercooling ions in an ultracold neutral plasma Daniel Crunkleton, Kyle Schneider, Kade Bishop, Scott Bergeson We present our progress in lasercooling ions in an ultracold neutral plasma. These plasmas are created by photoionizing lasercooled Ca atoms in a MOT. We lasercool using the strong $4s \rightarrow 4p$ transition at 397 nm. Optical pumping into the metastable dark state is prevented using two repumper lasers at 850 and 854 nm. We avoid coherences in the repumping scheme by rapidly and alternately modulating the intensity of the two repumping lasers. We present our calculations and preliminary data on cooling. [Preview Abstract] 

D1.00045: QUANTUM NETWORKS AND PROTOCOLS 

D1.00046: Towards Quantum Teleportation Between a Photonic Qubit and a Quantum Dot Spin State Jia Jun Wong, Jian Yang, Paul Kwiat Quantum teleportation plays a vital role in quantum computation and communication, as it provides an interface between dissimilar qubits, allowing the possibility to exploit experimental advantages presented in different quantum systems. For example, a quantum dot spin qubit can be used for long storage time while a telecom wavelength photonic qubit can be used for robust information transfer between distant parties. Here we are developing a narrowband singlephoton source with the aim of demonstrating quantum teleportation of a photonic state to a quantum dot spin state. To ensure high indistinguishability between the photon sources, cavityenhanced spontaneous parametric downconversion is used to generate narrowband photons of 200 MHz, matching the entangled spinphoton state emitted from the quantum dot. The source cavity mainly consists of three optical components in sequence, typeII nonlinear crystal (PPKTP), a KTP crystal for doubleresonance tuning and a concave output coupler. By placing a polarizing beam splitter after the source, a single photon can be heralded at an expected rate of 13 kHz. To achieve high fidelity, an electrooptic modulator can be used to match the frequencies of the downconversion and quantum dot photons. [Preview Abstract] 

D1.00047: Directional photon emission from entangled atomic ensembles Minho Kwon, Matt Ebert, Thad Walker, Mark Saffman Qubits encoded in long lived collective states of atomic ensembles can be mapped onto photonic modes for interconnecting atomic quantum memories. We have recently demonstrated state preparation, coherence, and blockade of atomic ensemble qubits [1,2]. The qubit state can be mapped onto a propagating mode by transfer to an optically excited state, followed by directional emission of a single photon. We calculate the characteristics of single photon emission from small atomic ensembles of less than 100 atoms prepared in \textbar W\textgreater states. The emission time and spatial distribution will be shown for experimentally relevant parameters. We show how the efficiency of coupling into a single mode fiber depends on the number of atoms, atomic density, aspect ratio of the ensemble, and randomness of the atomic positions.\\[4pt] [1] M. Ebert, A. Gill, M. Gibbons, X. Zhang, M. Saffman, and T. G. Walker, Atomic Fock state preparation using Rydberg blockade, Phys. Rev. Lett. 112, 043602 (2014). \newline [2] M. Ebert, M. Kwon, T. G. Walker, and M. Saffman, Coherence and Rydberg blockade of atomic ensemble qubits, arXiv:1501.0408 (2015). [Preview Abstract] 

D1.00048: Entangled optical clocks via Rydberg blockade Peter Komar, Eric Kessler, Turker Topcu, Andrei Derevianko, Mikhail Lukin We present an analysis of a protocol for creating fully entangled GHZtype states of atoms in spatially separated optical atomic clocks. In our scheme, local operations make use of the strong dipoledipole interaction between Rydberg excitations, which give rise to fast and reliable quantum operations involving all atoms in the ensemble. The necessary entanglement between distant ensembles is mediated by singlephoton quantum channels and collectively enhanced lightmatter couplings. These techniques can be used to create the recently proposed quantum clock network based on neutral atom optical clocks [1]. We specifically analyze the realization of this scheme based on neutral Yb atoms.\\[4pt] [1] Komar et al, Nature Physics 10, 582587 (2014) [Preview Abstract] 

D1.00049: PolarizationIndependent Photon Quantum Memorywith Variable Time Delay Michelle Victora, Jia Jun Wong, Paul Kwiat, Bradley Christensen, Kevin McCusker, Michael Goggin, Nick LaRacuente, Austin Graf A variable time delay photon quantum memory has many applications in quantum computation and communication. For instance, it provides precise synchronization of qubits, highly desirable in a quantum repeater architecture. Here, we are in the process of demonstrating a highefficiency ``digital'' photon storage system using multiple optical cavities to create variable storage times. These cavities have delay times of 12.5 ns, 125 ns, and 1.25 $\mu $s, with capabilities for multiple photon storage in various degrees of freedom [i.e., polarization, timing, spatial modes, etc.]. The freespace storage cavity system benefits from the availability of lowloss dielectric coatings, in order to attain higher transmission and larger optical bandwidth than current photon quantum memories based on fiber optic loops, atomic vapors, or solidstate media. [Preview Abstract] 

D1.00050: Cascading Quantum LightMatter Interfaces Mehdi Namazi, Thomas Mittiga, Connor Kupchak, Sam Rind, Eden Figueroa We present, for the first time to our knowledge, the cascading storage of few photon pulses in a room temperature quantum memory based on Electromagnetically Induced Transparency. The interface is realized in $^{\mathrm{87}}$Rb gas and by using a powerful control field which is filtered out through our filtering system. The retrieval control field pulse has been temporally reshaped in amplitude in order to preserve the temporal shape of the signal pulse after the storage. This signal pulse then is sent back to the quantum memory as the input for a sequential storage. The cascadability of the quantum memory is tested with both classical light and weak coherent input pulses containing on average 8 photons. In the latter case, an efficiency of 14.6{\%} with a signaltobackgroundratio of (SBR) 13 has been recorded for the first storage. Including the lost in the system and the storage efficiency, the stored pulse contains on average 0.6 photons. This pulse is again stored with an efficiency of 22.9{\%} with SBR of 1.2. [Preview Abstract] 

D1.00051: Characterization and Mitigation of Anomalous Motional Heating in SurfaceElectrode Ion Traps Robert McConnell, Colin Bruzewicz, John Chiaverini, Jeremy Sage Anomalous motional heating represents a major obstacle to scalable quantum information processing with trapped ions. We present experimental investigations to understand and overcome anomalous motional heating in surfaceelectrode ion traps. We characterize the observed heating rate of a single trapped ion in terms of its dependence on trap frequency and temperature and compare with several theoretical noise models. We also investigate the possible amelioration of this effect through different surface preparation techniques. [Preview Abstract] 

D1.00052: Microfabrication of Surface Ion Trap Chip and State Manipulation of Single 171Yb$+$ Qubit Seokjun Hong, Minjae Lee, Hongjin Cheon, Jun Sik Ahn, Taehyun Kim, Dongil "Dan" Cho Ion traps are one of the promising physical implementations of quantum information processing. This paper presents new ion trap chips using a copper sacrificial layer. Boundary element method (BEM) simulation results show that the fabricated ion trap chip has a trap depth of 0.063 eV at 81 um above the top electrodes and radial secular frequencies of 1.52 and 1.6 MHz. Up to six 174Yb$+$ ions and three 171Yb$+$ ions have been successfully trapped. This paper also demonstrates the state manipulation of single 171Yb$+$ qubit through Rabi oscillation induced by microwave with frequency of 12.628 GHz. Using the new copper sacrificial method, accurate overhang dimensions that can effectively shield stray electric fields from dielectric layers, which in turn can reduce the micromotion of trapped ions, can be achieved. Acknowledgement: This work was partially supported by ICT R{\&}D program of MSIP/IITP. [10043464 , Development of quantum repeater technology for the application to communication systems] [Preview Abstract] 

D1.00053: A modular barium ion trap experiment for quantum information and remote entanglement James Siverns, Qudsia Quraishi Trapped ions remain a leading candidate for the implementation of largescale quantum networks. Promising schemes include quantum information processing using deterministic local ion entanglement with ion chains and heralded remote entanglement using photonic links between separate nodes in a quantum network. In particular, trapped barium ions possess the ability to emit entangled single photons in the visible spectrum making them a promising candidate as a photonic link. We present a design for a modular barium ion trap experiment that is suitable for both local quantum information processing and as a node in a larger quantum network. We are currently in the process of building a segmented fourblade Paul trap which is known for its versatile trapping of both a single ion and a chain of ions. Traps of this type (R. Blatt and D. Wineland, Nature, vol. 453, p. 1081015 (2008)) allow collection of large solid angles of emitted photons without obstruction from trap electrodes and, therefore, can increase remote entanglement rates. We also plan to implement quantum frequency conversion so as to demonstrate a system that is compatible with remote entanglement protocols and quantum frequency conversion for entanglement over large distances. [Preview Abstract] 

D1.00054: ATOMIC CLOCKS 

D1.00055: Search for variation of the finestructure constant using optical clock transitions in Cf$^{15+}$, Es$^{17+}$ and Es$^{16+}$ ions Ulyana Safronova, Vladimir Dzuba, Marianna Safronova, Victor Flambaum We study optical transitions in Cf$^{15+}$, Es$^{17+}$ and Es$^{16+}$ ions using the highprecision relativistic method that combines the configuration interaction and linearized coupledcluster approaches. We identify the transitions that are extremely sensitive to the variation of the finestructure constant. The sensitivities are the largest among all atomic systems studied so far. These transitions have all features for the implementation of the ultraprecision optical atomic clocks for test of the $\alpha$variation at extremely high accuracy of 10$^{20}$ per year. [Preview Abstract] 

D1.00056: Development of a compact cold atom clock with a cylindrical cavity Liang Liu, Huadong Cheng, Peng Liu, Yanling Meng, Jinyin Wan, Xiumei Wang, Yanning Wang, Ling Xiao The development of a compact cold atom clock with an integrating sphere is described. Rubidium atoms are cooled by diffuse light generated by injecting lasers into a cylinder with high diffuse reflection of light at the inner surface. We measured the number, temperature, distribution, and lifetime of cold atoms in the cylinder. A special method to control the cold atom distribution in the cylinder is developed in order to improve the signal to noise ratio of the cold atom clock. The cylinder is also used as a microwave cavity with TE011 [1], which is designed and manufactured for a cold rubidium atom clock. We will report the recent progress on the newlydesigned cold atom clock. In this design, the polarization detection rather than absorption detection [2] is used to detect the cold atoms, by which the contrast of the signal is greatly increased.\\[4pt] [1] Meng, Y.L. {\it et al.}, Phys. Lett. A 378, 2034 (2014)\\[0pt] [2] Zheng, B.C. {\it et al.}, Chin. Phys. Lett. 31, 073701 (2014) [Preview Abstract] 

D1.00057: Mitigating aliasing in atomic clocks Hermann Uys, Ismail Akhalwaya, Jarrah Sastrawan, Michael Biercuk Passive atomic clocks periodically calibrate a classical local oscillator against an atomic quantum reference through feedback. The periodic nature of this correction leads to undesirable aliasing noise. The Dick Effect, is a special case of aliasing noise consisting of the downconversion of clock noise at harmonics of the correction frequency to a frequency of zero. To combat the Dick effect and aliasing noise in general, we suggest an extension to the usual feedback protocol, in which we incorporate information from multiple past measurements into the correction after the most recent measurement, approximating a crude low pass antialiasing filter of the noise. An analytical frequency domain analysis of the approach is presented and supported by numerical time domain simulations. [Preview Abstract] 

D1.00058: Precision Measurements with a Molecular Clock Andrew Grier, Mickey McDonald, Bart McGuyer, Geoffrey Iwata, Florian Apfelbeck, Marco Tarallo, Tanya Zelevinsky We report on recent results obtained with photoassociated Sr2 molecules confined in a lattice. Sr2 has a range of electronically excited bound states which are readily accessible with optical wavelengths using the narrow 1S0>3P1 intercombination line. As in Nat. Phys. 11, 32, we measure the lifetimes of the narrow, deeplybound subradiant states in the 1g (1S0+3P1 dissociative limit) potential, allowing for coherent control of molecules and a comparison with theoretical predictions of the lifetimes and transition strengths of these states. Next, we study ultracold photodissociation of Sr2 molecules through abortion of one and two photons near the atomic intercombination line. This allows us to observe the vector character of transition elements through the angular dissociation pattern and to directly measure barrier heights in the excited state potentials. Finally, as shown in PRL 114, 023001, we demonstrate that in a nonmagic lattice, a narrow transition can be used to measure the trapped gas temperature through the linewidth of the spectral feature corresponding to the carrier transitions. We use this technique to measure the temperature of Sr2 molecules to ~10x higher precision than with standard techniques. We discuss future prospects with this molecular lattice clock. [Preview Abstract] 

D1.00059: Controlling higherorder Stark effects in an Yb optical lattice clock W.F. McGrew, N.B. Phillips, K. Beloy, N. Hinkley, M. Schioppo, J.A. Sherman, T.H. Yoon, C.W. Oates, A.D. Ludlow Recently, optical lattice clocks have demonstrated fractional frequency stability at the $10^{18}$ level. Agreement between two Sr clocks has been observed at $1.1\pm1.6\times10^{18}$ [I. Ushijima $\textit{et al.}$, arXiv:1405.4071 (2014)], with estimates of total uncertainty at similar levels. For the NIST Yb optical lattice clock, we have begun an experimental evaluation of all systematic uncertainties. The blackbody Stark shift  until recently the leading source of uncertainty  is controlled with a roomtemperature radiative thermal shield to a fractional clock uncertainty of $1\times10^{18}$. The next most significant effect is due to the optical lattice itself. We used a powerenhancement cavity to study the shift for both deep and shallow lattices with diverse thermal occupations. Hyperpolarizability effects can be significant at this level, and are precisely measured. Scalar Stark and hyperpolarizability lattice effects can be canceled to maintain total lattice shifts at $<10^{17}$. We also report experimental measurements of the Stark shifts due to the probe laser field and stray static electric fields. [Preview Abstract] 

D1.00060: Progress with a green astrocomb for exoplanet searches ChihHao Li, Alexander G. Glenday, David F. Phillips, Nicholas Langellier, Guoqing Chang, Gabor Furesz, Franz X. Kaertner, Dimitar Sasselov, Andrew Szentgyorgyi, Ronald L. Walsworth Searches for extrasolar planets using the precision stellar radial velocity (RV) measurement technique are approaching Earthlike planet sensitivity. Astrocombs, which consist of a laser frequency comb, coherent wavelength shifting mechanism (such as a doubling crystal and photonic crystal fiber), and a modefiltering FabryPerot cavity (FPC), provide a promising route to increased accuracy and longterm stability on the astrophysical spectrograph calibration. We first present the design of a green astrocomb from an octave spanning Ti:Sapphire laser, spectrally broadened by custom tapered PCF to the visible band via fiberoptic Cherenkov radiation for frequency shifting, and filtered by a broadband FPC, constructed by a pair of complementary chirped mirrors. We also present results from two years of operation of the astrocomb calibrating the HARPSN spectrograph at the Italian National Telescope on La Palma, Canary Islands, including its use in measurements of solar radial velocities as well as its use in searches for extrasolar planets. [Preview Abstract] 

D1.00061: Detecting Gravitational Wave Time Dilation Using SpaceBased Atomic Clocks Nicholas Langellier, Shimon Kolkowitz, Avi Loeb, Mikhail Lukin, Dani Maoz, Jun Ye, Ronald Walsworth Recently, atomic clocks have reached a fractional frequency instability of about 10$^{\mathrm{16}}$/$\surd \tau $. With such precision it may be possible to measure differences in the ticking rates of a spacedbased network of atomic clocks due to time dilation induced by passing gravitational waves. Supermassive black hole binaries arising from galaxy mergers at cosmological distances are predicted to produce gravitational waves at mHz frequencies. The largest variations in clock ticking will occur on the scale of half a wavelength, which for mHz waves is on the 1 AU scale. We assess the sensitivity and feasibility of such a space clock network detector, and compare it to existing means of mHz gravitational wave detection. [Preview Abstract] 

D1.00062: A Sr clock with total uncertainty of $2\times 10^{18}$ and development of the new apparatus G. Edward Marti, Rees Mcnally, Travis Nicholson, Sara Campbell, Ross Hutson, Jun Ye We report on improvements to the accuracy and stability of the JILA Sr clock, with a record total clock uncertainty of $2.1\times 10^{18}$ and stability of $2.2\times 10^{16}/\sqrt{\mathrm{Hz}}$. By choosing a lattice wavelength such that the scalar and tensor shifts cancel, we observe no measurable shift in the clock frequency with trap intensity. We reduce the blackbody radiation shift uncertainty with accurate in vacuum thermometry, traceable to the NIST ITS90 temperature scale, and with an improved determination of the dynamical correction coefficient by measuring the ${}^3 D_1$ lifetime to $0.5\%$. We also discuss progress on a new apparatus for fermionic quantum degenerate strontium in a threedimensional magicwavelength optical lattice. We will implement rapid evaporative cooling to achieve quantum degeneracy with a duty cycle compatible with clock measurements, shorter than the coherence time of the local oscillator. Loading the sample into the lowest band of a 3D lattice will enable high densities and atom numbers with minimal interaction shifts. The apparatus will be used to explore spinorbit coupling, quantum magnetism, and improve the precision of future lattice clocks. [Preview Abstract] 

D1.00063: PRECISION MEASUREMENTS 

D1.00064: Radiokrypton dating with Atom Trap Trace Analysis Wei Jiang, Jake Zappala, Kevin Bailey, ZhengTian Lu, Peter Mueller, Thomas O'Connor The longlived noblegas isotope~$^{\mathrm{81}}$Kr is the ideal tracer for old water and ice in the age range of 10$^{\mathrm{5}}$~ 10$^{\mathrm{6}}$~years, a range beyond the reach of~$^{\mathrm{14}}$C.~~$^{\mathrm{81}}$Krdating, a concept pursued over the past four decades by numerous laboratories employing a variety of techniques, is now available for the first time to the earth science community at large.~ This is made possible by our development of the Atom Trap Trace Analysis (ATTA) method, in which individual atoms of the desired isotope are captured and detected with superior selectivity in a laserbased atom trap. Thus far, ATTA has been used to analyze~$^{\mathrm{81}}$Kr,~$^{\mathrm{85}}$Kr, and $^{\mathrm{39}}$Ar, which have extremely low isotopic abundances (10$^{\mathrm{16}}$~to 10$^{\mathrm{11}})$, and cover a wide range of ages and applications.~ In collaboration with earth scientists, we are dating groundwater in major aquifers around the world as well as polar ice from Antarctica. [Preview Abstract] 

D1.00065: Highprecision Starkshift measurements in excited states of indium using an atomic beam Benjamin Augenbraun, Priyanka Rupasinghe, Protik Majumder In recent years, we have pursued a series of precise atomic structure measurements in Group III elements thallium and indium to test \emph{ab initio} theory calculations in these threevalenceelectron systems. Our measurement of the indium scalar polarizability within the 410 nm $5p_{1/2} 6s_{1/2}$ was in excellent agreement with a new atomic theory calculation. We are now measuring the scalar polarizability within the $6s_{1/2}  6p_{1/2}$ excitedstate transition. In our experiment, two external cavity semiconductor diode lasers interact transversely with a collimated indium atomic beam. We lock the 410 nm laser to the $5p_{1/2}  6s_{1/2}$ transition, and overlap a 1343 nm infrared laser to reach the $6p_{1/2}$ state. The very small infrared absorption in our atomic beam is detected using FM spectroscopy. Sideband features in our demodulated spectrum offer builtin frequency calibration. We apply electric fields up to 20 kV/cm to the atomic beam to observe Stark shifts of order 100 MHz for this excited state. Comparing our polarizability value to theoretical predictions will lead to precise new values of $6p5d$ matrix elements in indium. The same infrared laser will be used to study the scalar and tensor polarizabilty of the $6p_{3/2}$ state in a future experiment. [Preview Abstract] 

D1.00066: Active and Passive Interferometric Fringe Stabilization for Quantum Communications in Space Joseph Chapman, Trent Graham, Paul Kwiat In interferometry, the relative phase between the paths is liable to drift over time due to environmental factors, i.e., vibrations in the components and from turbulence and temperature fluctuations in the air. If timebin encoded photons are received from a moving space platform, e.g., a satellite or the International Space Station, there would be an additional large relative temporal shift because of the movement of the source toward or away from the receiver. This shift would alter the temporal coherence of adjacent timebinsas measured by a suitable temporallyunbalanced interferometerin addition to the relative phase errors from the environment. To achieve accurate measurements in this situation, the interferometer needs to be stabilized against phase drifts. We have employed an active and passive stabilization scheme for a double unbalanced MachZehnder interferometer configuration; while passive damping reduces most of the phase drift due to vibrations and fluctuations from the air, we designed and implemented an active feedback correction system to stabilize the remaining phase drift and the simulated temporal drift. [Preview Abstract] 

D1.00067: Precision spectroscopy of the 2S4P transition in atomic hydrogen Lothar Maisenbacher, Axel Beyer, Ksenia Khabarova, Arthur Matveev, Randolf Pohl, Thomas Udem, Theodor W. H\"{a}nsch, Nikolai Kolachevsky A precision measurement of the 2S4P transition in atomic hydrogen, when combined with the precisely known 1S2S transition frequency\footnote{C.$\,$G. Parthey et al., PRL 107, 203001 (2011)}, can be used to determine the value of the r.m.s.$\,$proton charge radius $r_p$. We report on our progress towards an absolute frequency measurement, using a cryogenic beam of atoms optically excited to the metastable 2S state\footnote{A. Beyer et al., Ann.$\,$Phys.$\,$525, 671 (2013)}. This strongly suppresses the first order Doppler shift, which is further reduced using actively stabilized counterpropagating laser beams for the 2S4P (onephoton) excitation. We experimentally verify this suppression using timeofflight resolved detection. We present a theoretical and experimental study of interference effects due to spontaneous emission\footnote{M. Horbatsch and E.$\,$A. Hessels, PRA 82, 052519 (2010)} and the corresponding line center shifts, using a segmented detector to spatially resolved the emission pattern. An experimental scheme to suppress this systematic shift and extract the unperturbed transition frequency is shown and future measurements of transitions to higher $nL$ states are discussed. [Preview Abstract] 

D1.00068: Measurement of the anapole moment of 133 Cesium from Parity Nonconserving (PNC) interaction in hyperfine ground states Jungu Choi, George Toh, Daniel Elliott We discuss initial work towards a measurement of the anapole moment of 133 Cesium from a parity nonconserving (PNC) interaction between the hyperfine ground states. The result of the previous measurement of this anapole moment by the Boulder group, carried out on the 6S$_{\mathrm{/2}}$ $\to$ 7S$_{\mathrm{/2}}$ transition, was much larger than expected, and is at odds with various measurements of scattering cross sections. In an effort to address this deviation, we propose to observe the PNC effect on the hyperfine ground state 6S$_{\mathrm{/2}}$F $=$ 3 $\to$ 6S$_{\mathrm{/2}}$F $=$ 4 transition by exciting the microwave and twophoton Raman transitions, and observing the interference between these interactions. The benefits of this proposed measurement include the wellknown microwave transition frequency (atomic clock frequency), far less sensitivity to the stray field effects, and a high excitation rate by the Raman transition. [Preview Abstract] 

D1.00069: Nuclear Spin Dependent Parity Violation in Diatomic Molecules Emine Altuntas, Jeffrey Ammon, Sidney Cahn, David DeMille, Mikhail Kozlov, Richard Paolino Nuclear spindependent parity violation (NSDPV) effects arise from exchange of the $Z^{0}$ boson between electrons and the nucleus, and from interaction of electrons with the nuclear anapole moment, a parityodd magnetic moment. The latter scales with nucleon number of the nucleus $A$ as $A^{2/3}, $whereas the $Z^{0}$ coupling is independent of $A$. Thus the former is the dominant source of NSDPV for nuclei with $A\ge $\textit{20}. We study NSDPV effects using diatomic molecules, where signals are dramatically amplified by bringing rotational levels of opposite parity close to degeneracy in a strong magnetic field. Using a Starkinterference technique we measure the NSDPV interaction matrix element. We present results that demonstrate statistical sensitivity to NSDPV effects surpassing that of any previous atomic parity violation measurement, using the test system~$^{\mathrm{138}}$Ba$^{\mathrm{19}}$F. We also discuss investigations of systematics due to nonreversing stray $E$fields, $E_{nr}$ together with $B$field inhomogeneities, and shortterm prospects for measuring the nuclear anapole moment of $^{\mathrm{137}}$Ba. In the long term, our technique is sufficiently general and sensitive to enable measurements across a broad range of nuclei. [Preview Abstract] 

D1.00070: Frequencyoffset separated oscillatory fields technique N. Bezginov, A.C. Vutha, I. Ferchichi, C.H. Storry, E.A. Hessels Improved measurements in atomic hydrogen are needed to shed light on the proton radius puzzle. We are measuring the Lamb shift in hydrogen ($n=2, S_{1/2} \to P_{1/2}$) using a frequencyoffset separated oscillatory fields (FOSOF) method. The advantages of this method include its insensitivity to atomic beam intensity fluctuations and the microwavesystem frequency response. We present experimental results obtained with this method, towards a new measurement of the proton charge radius. [Preview Abstract] 

D1.00071: Laser Frequency Stabilization Using a Calcium RamseyBord\'e Interferometer Judith Olson, Richard Fox, Eduardo de CarlosLopez, Chris Oates, Andrew Ludlow RamseyBord\'e (RB) interferometry is a powerful spectroscopic tool for the interrogation of narrow optical resonances. Even for atomic systems with broad velocity distributions, spectral features free from firstorder Doppler and transittime broadening can be resolved using two counterpropagating pairs of copropagating beams. In our system, a highflux thermal calcium beam is excited from the $^1 S_0$ to $^3 P_1$ state using the 657 nm intercombination line. The high spectral resolution afforded by RB interferometry allows exploration of spectral features approaching the transition's natural linewidth, 400 Hz. Together with the large atom number from the continuously fed thermal beam, the optical frequency reference has considerable potential for a compact frequency standard with extremely low instability. We previously observed fractional frequency instability of $5.5 \times 10^{15}$ at 1s using this technique. With the addition of a laser to access the strong 431 nm cycling transition from the $^3 P_1$ to the doubly excited $^3 P_0$ state, the potential exists to achieve frequency stability below $10^{16}$ at short times. We explore the implementation of this system and future enhancements to further improve the standard's short and longterm performance. [Preview Abstract] 

D1.00072: New State of Fermionic Matter Miron Amusia, Vasily Shaginyan In many Fermi systems and compounds at zero temperature a phase transition happens that leads to a quite specific state called fermion condensation. As a signal of such a fermion condensation quantum phase transition serves unlimited increase of the effective mass of quasiparticles that determines the excitation spectrum and creates flat bands [1]. We have theoretically carried out a systematic study of the phase diagrams of strongly correlated heavyfermion compounds, including heavyfermion metals, high temperature superconductors, insulators with strongly correlated quantum spin liquid, quasicrystals, and two dimensional Fermi systems (like $^{3}$He), and have demonstrated that these diagrams have universal features. The obtained results are in good agreement with experimental facts. We have shown that the data collected on these very different heavyfermion compounds have a universal scaling behavior. Thus, the quantum critical physics of different heavyfermion compounds is universal. This uniform behavior, allows us to view it as the new state of matter.\\[4pt] [1] M. Ya. Amusia et al, \textit{Theory of HeavyFermion Compounds}, Springer Series in SolidState Sciences \textbf{182,} (2014). [Preview Abstract] 

D1.00073: New Prospects for Atomic Parity Violation Benjamin Roberts, Vladimir Dzuba, Victor Flambaum We have performed calculations of parity violating effects for several heavy elements in which the effect is greatly enhanced due to the presence of very closely spaced atomic and nuclear states of opposite parity. Also, recently, an optical cavity that can enhance parity violating signals by around 4 orders of magnitude has been developed. If combined with the further parity violation enhancement found in diatomic molecules, this signal enhancement can be significantly increased. So far, a successful measurement of parity violation in molecules has not been achieved. Theoretical considerations are crucial for success in this field. Accurate calculations are required in order to interpret the measurements in terms of fundamental physics parameters, and also to identify suitable systems for study. We perform calculations of parity violation (optical rotation) for molecules suitable for the ``optical cavity enhanced''type measurements discussed above. With these calculations we identify candidates especially suitable for the measurements in order to maximise the parityviolating effect without detrimentally affecting the sensitivity and systematics. [Preview Abstract] 

D1.00074: Searching for nonNewtonian gravity at the micron scale with lasercooled nanospheres Gambhir Ranjit, David Atherton, Mark Cunningham, Jose Valencia, Andrew Geraci, Hart Goldman Several theories beyond the standard model predict the deviation of gravity from the Newtonian model at short range. An optically levitated and cooled silica nanosphere in vacuum has a high quality factor resulting in ultrahigh sensitivity; hence it provides a promising tool to measure such deviations [1]. I will discuss the experiment we are developing to test nonNewtonian gravity at the micron length scale. In addition, I will also present the prospect of sensing shortrange forces between a surface and a free falling nanosphere in a Talbot matterwave interferometer [2].\\[4pt] [1] Andrew A. Geraci, Scott B. Papp, John Kitching, Phys. Rev. Lett. 105,101101 (2010).\\[0pt] [2] Andrew A. Geraci, Hart Goldman, arXiv:1412.4482(2014). [Preview Abstract] 

D1.00075: QUANTUM OPTICS 

D1.00076: Atomsurface studies with Rb Rydberg atoms Yuanxi Chao, Jiteng Sheng, Jonathon Sedlacek, James Shaffer We report on experimental and theoretical progress studying atomsurface interactions using rubidium Rydberg atoms. Rydberg atoms can be strongly coupled to surface phonon polariton (SPhP) modes of a dielectric material. The coherent interaction between Rydberg atoms and SPhPs has potential applications for quantum hybrid devices. Calculations of TMmode SPhPs on engineered surfaces of periodically poled lithium niobate (PPLN) and lithium tantalate (PPLT) for different periodic domains and surface orientations, as well as natural materials such as quartz, are presented. Our SPhP calculations account for the semiinfinite anisotropic nature of the materials. In addition to theoretical calculations, we show experimental results of measurements of adsorbate fields and coupling of Rydberg atoms to SPhPs on quartz. [Preview Abstract] 

D1.00077: Generation of heralded Dicke state Chern Hui Lee, Kyle Arnold, Markus Baden, Murray Barrett We study experimentally the efficient creation of heralded Dicke states in an atomic ensemble trapped in a high finesse optical cavity. Weak resonant light in freespace mode transverse to the cavity is efficiently absorbed by the optically dense sample. Subsequent stimulated Raman scattering into the cavity mode dominates over free space scattering because of the high single atom cooperativity of the cavity. This result paves the way towards a high efficiency heralded quantum memory which will be practically useful for storing the polarization state of a single photon. [Preview Abstract] 

D1.00078: Ultranarrow EIA spectra of $^{85}$Rb atom in a degenerate Zeeman multiplet system Hafeez Ur Rehman, Muhammad Mohsin Qureshi, HeungRyoul Noh, JinTae Kim Ultranarrow EIA spectral features of thermal $^{85}$Rb atom with respect to coupling Rabi frequencies in a degenerate Zeeman multiplet system have been unraveled in the cases of same ($\sigma^+  \sigma^+$, $\pi \parallel \pi$ ) and orthogonal ($\sigma^+  \sigma^$, $\pi \perp \pi$ )polarization configurations. The EIA signals with subnatural linewidth of $\sim$ 100 $kHz$ even in the cases of same circular and linear polarizations of coupling and probe laser have been obtained for the first time theoretically and experimentally. In weak coupling power limit of orthogonal polarization configurations, timedependent transfer of coherence plays major role in the splitting of the EIA spectra while in strong coupling power, Mollow tripletlike mechanism due to strong power bring into broad split feature. The experimental ultranarrow EIA features using one laser combined with an AOM match well with simulated spectra obtained by using generalized timedependent optical Bloch equations. [Preview Abstract] 

D1.00079: A Full Quantum Multimode Treatment of an Atom in a Waveguide William Konyk, Julio GeaBanacloche We apply a full multimode treatment of the quantized electric field to a single two level atom in a bidirectional waveguide, a system that has been proposed for ``photon sorting'' and other quantum information processing tasks. Starting with a photon pulse consisting of an arbitrary number of photons, all with the same pulse shape, we derive the equations of motion and an expression for the shape of the pulse after its interaction with the atom. For a two photon Gaussian pulse, and for a ``flattop pulse'' composed of error functions, we consider the shape of the final spectrum and the nonclassical nature of the light. We find that with a small coupling between the atom and the field modes there exists a region where the output light is strongly antibunched with a high probability of singlephoton detection. We also explore the reflection and transmission properties of the atom along with detection probabilities of the photons on each channel. [Preview Abstract] 

D1.00080: Coherent interactions between matter and radiation in neutral hydrogen clouds in the interstellar medium Fereshteh Rajabi, Martin Houde We investigate the possibility of coherent interactions between matter and radiation in neutral hydrogen (HI) clouds in the interstellar medium (ISM), with the goal of determining their impact on the measurement of the abundance of the atomic hydrogen. Currently, astrophysicists assume that the interaction between matter and radiation is fully noncoherent in the ISM, and calculate hydrogen abundance based on this assumption. We reexamine this assumption by adapting Dicke's coherence formalism to different sets of initial conditions in HI clouds in the ISM and by determining the intensity in different ensembles of atoms. We compare this intensity with the one calculated with the noncoherent radiation model, and discuss the importance of potential corrections in abundance measurements. In this study, we have derived the MaxwellBloch (MB) equations for an ensemble of N hydrogen atoms interacting with the 21 cm line. The MB equations are solved analytically in the linear regime including homogeneous dephasing mechanisms existing in the ISM. In the nonlinear regime, the MB equations are solved numerically for 1) the ideal case where all dephasing mechanisms are neglected, 2) for the case of equal dephasing times. The results suggest possibility of coherent interactions. [Preview Abstract] 

D1.00081: Suppression of collective quantum jumps in Rydberg atoms by collective spontaneous emission Lyndon Cayayan, Jacob Pauley, James Clemens We consider a system of driven, damped Rydberg atoms with dipoledipole energy shifts which can give rise to Rydberg blockade when the atoms are driven on resonance and collective quantum jumps when the atoms are driven off resonance. For the damping we consider both independent and collective spontaneous emission. For independent emission a quasiclassical model predicts a bistable steady state and quantum fluctuations drive collective jumps between the two bistable branches. We show that collective spontaneous emission strongly suppresses the bistability and therefore suppresses the collective quantum jumps. [Preview Abstract] 

D1.00082: Geometry dependent suppression of collective quantum jumps in Rydberg atoms Eitan Lees, James Clemens We consider $N$ driven, damped Rydberg atoms in different spatial arrangements. Treating the atoms as twolevel systems we model the coupling to the environment via the LehmbergAgarwal master equation which interpolates between fully independent and fully collective spontaneous emission depending on the specific locations of the atoms. We also include a collective dipoledipole energy shift in the excited Rydberg state which leads to collective quantum jumps in the atomic excitation when the system is driven off resonance. We show that the quantum jumps are suppressed as the system makes a transition from independent to collective emission as the spacing of a linear array of atoms is decreased below the emission wavelength. [Preview Abstract] 

D1.00083: Ultrasensitive atomic spin measurements with a nonlinear interferometer Robert J. Sewell, Mario Napolitano, Naeimeh Behbood, Giorgio Colangelo, Ferran Martin Curiana, Morgan W. Mitchell We study nonlinear interferometry applied to a measurement of atomic spin and demonstrate a sensitivity that cannot be achieved by any linearoptical measurement with the same experimental resources. We use alignmenttoorientation conversion, a nonlinearoptical technique from optical magnetometry, to perform a nondestructive measurement of the spin alignment of a cold Rb87 atomic ensemble. We observe stateoftheart spin sensitivity in a singlepass measurement, in good agreement with covariancematrix theory. Taking the degree of measurementinduced spin squeezing as a figure of merit, we find that the nonlinear technique's experimental performance surpasses the theoretical performance of any linearoptical measurement on the same system, including optimization of probe strength and tuning. The results confirm the central prediction of nonlinear metrology, that superior scaling can lead to superior absolute sensitivity. Reference: Sewell, et al. Phys. Rev. X 4, 021045 (2014) [Preview Abstract] 

D1.00084: Optical pumping of multiple atoms in the single photon subspace of twomode cavity QED Ka Wa Yip, James Clemens We consider $N$ four level atoms coupled to an orthogonally polarized, degenerate twomode optical cavity. Starting with the atoms prepared in one of the degenerate ground states a single photon introduced into the driven cavity mode will be recycled to pump multiple atoms to the other ground state. For two atoms we analytically calculate the steady state using quantum trajectory equations and show that the system makes stochastic transitions between two different subspaces with the transition correlated with the emission of a polarized photon from one of the two modes of the cavity. In this way the long time evolution of the atomic state can be monitored by direct photodetection of the cavity decay passed through a polarizing beam splitter. We also investigate the dynamics of the approach to the steady state by numerical simulations carried out using the Quantum Toolbox in Python (QuTiP). [Preview Abstract] 

D1.00085: Pump/Probe Angular Dependence of Hanle Electromagnetically Induced Transparency Richard Jackson, Kaleb Campbell, Michael Crescimanno, Samir Bali We investigate the dependence of Hanle Electromagnetically Induced Transparency (EIT) on angular separation between pump and probe field propagation directions in roomtemperature Rb vapor. We observe the FWHM of the probe transmission spectrum and the amplitude of the EIT signal while varying the angular separation from 0 to 1 milliradian. Following the work of M. Shuker, O. Firstenberg, R. Pugatch, A. BenKish, A. Ron, and N. Davidson, Phys. Rev. A 76, 023813 (2007), we examine potential applications in information storage and retrieval. [Preview Abstract] 

D1.00086: Spectral Filtering Using LowLoss Diffraction Gratings Chris Zeitler, David Schmid, Paul Kwiat Certain tasks in optics, such as loopholefree tests of Bell inequalities, require the use of narrow bandpass spectral filters with strict resolution and efficiency requirements due to the broad bandwidth of the entangled photons. Spectral filters based on diffraction gratings suffer from high levels of loss due to light leakage into undesired spatial modes. However, recent developments in resonant alldielectric diffraction gratings have allowed diffraction efficiencies into the desired mode to exceed 99 percent. Additionally, the geometric nature of these filters allows tuning of the bandwidth, resolution, and efficiency over a wide range to suit a variety of applications. We demonstrate the use of the gratings as a broadband filter of a downconversion source, heralding the conjugate spectrum in the photon which never hits the diffraction grating. We also use optical masks in conjunction with the gratings to create unusuallyshaped spectra, such as exponentials and step functions. Finally, we show that the gratings can be used to make narrowband filters with bandwidths as low as 30 picometers. [Preview Abstract] 

D1.00087: Quantum Optics in the Solid State with Diamond Nanophotonics Nathalie de Leon, Ruffin Evans, Kristiaan De Greve, Michael Goldman, Alex High, Matthew Markham, Alastair Stacey, Daniel Twitchen, Marko Loncar, Hongkun Park, Mikhail Lukin Largescale quantum networks will require efficient interfaces between photons and stationary quantum bits. Nitrogenvacancy (NV) centers in diamond are a promising candidate for quantum information processing because they are optically addressable, have spin degrees of freedom with long coherence times, and as solidstate entities, can be integrated into nanophotonic devices. An enabling feature of the NV center is its zerophonon line (ZPL), which acts as an atomlike cycling transition that can be used for coherent optical manipulation and readout of the spin. However, the ZPL only accounts for 35{\%} of the total emission, and previously demonstrated methods of producing high densities of NV centers yield unstable ZPLs.~ We have developed techniques to fabricate high quality factor, small mode volume photonic crystal cavities directly out of diamond, and to deterministically position these photonic crystal cavities so that a stable NV center sits at the maximum electric field. We observe an enhancement of the spontaneous emission at the cavity resonance by a factor of up to 100. Crucially, we are able to control the NV center precisely using both microwave and resonant optical manipulation. These nanophotonic elements in diamond will provide key building blocks for quantum information processing such as single photon transistors, enabling distribution of entanglement over quantum networks. [Preview Abstract] 

D1.00088: MicronScale Magnetic Imaging of Meteorites and EarlyEarth Rocks with NV Centers in Diamond David Glenn, David LeSage, Roger Fu, Benjamin Weiss, Ronald Walsworth We use nitrogen vacancy (NV) centers in diamond to perform micronscale imaging of magnetic fields produced by rocks of meteoric and terrestrial origin. The combination of spatial resolution and magnetic sensitivity of the NV magnetic imager permits magnetic analyses of previously inaccessible geological samples. We employ this technique to map magnetic fields in chondrules from the Semarkona meteorite, helping to constrain the magnitudes of nebular magnetic fields which likely played a key role in accretion disk dynamics during the formation of the solar system. We also apply NV magnetic imaging to the study of earlyEarth rocks. [Preview Abstract] 

D1.00089: Biomagnetic Imaging Applications using NV Centers in Diamond David Glenn, David LeSage, Colin Connolly, Ronald Walsworth We present new measurements of magnetic fields produced by a range of biological specimens using a widefield magnetic imaging system based on NV centers in diamond. In particular, we show (i) the first magnetic images of a previously unstudied strain of magnetotactic bacteria, and (ii) a general platform for magnetic imaging of immunomagnetically labeled cells, which provides a useful alternative to traditional immunofluorescence techniques in the presence of strong autofluorescence and/or optically scattering media [Preview Abstract] 

D1.00090: A compact system for single site atom loading of a neutral atom qubit array Brad Dinardo, Steven Hughes, Sterling McBride, Joey Michalchuk, Dana Z. Anderson We present progress towards single atom loading from a magneto optical trap reservoir to a bottle beam (BoB) array trap site for use in quantum computation. Our procedure involves vertically transporting cesium atoms via a moving molasses MOT from a 3D MOT chamber into a six sided, ARcoated, high optical access UHV science chamber. The cesium atoms are to be horizontally displaced 100~$\mu $m to a 7 x 7 array of bluedetuned BoB traps. Displacement of the atoms will be accomplished by means of a moving standing wave dipole trap. The singlesite loading experiment will take place in the Atomic Qubit Array Cell (AQuA Cell) which is a compact, high performance UHV system that utilizes new miniature silicon and glass ion pump technology. The entire AQuA Cell is 0.6 liters. The cell, cooling, and transport optomechanics is incorporated in a package occupying about 0.028 cubic meters. [Preview Abstract] 

D1.00091: Quantum optics with siliconvacancy centers in diamond Denis Sukachev, Ruffin Evans, Alp Sipahigil, Michael Burek, Kay Jahnke, Lachlan Rogers, Fedor Jelezko, Kristiaan De Greve, Nathalie de Leon, Christian Nguyen, Hongkun Park, Marko Loncar, Mikhail Lukin The silicon vacancy is a color center in diamond with spectrally stable and bright optical transitions. We demonstrated twophoton interference from separated SiV centers, measured electronic spin lifetime (2.4ms) and coherence (35ns) via coherent population trapping, and carried out time resolved fluorescence measurements to identify electronphonon relaxation mechanisms that limit the spin coherence time. Ways to extend spin coherence times and recent experiments where a single SiV center is coupled to a nanophotonic crystal cavity are also discussed. [Preview Abstract] 

D1.00092: Towards a Quantum Spin Transducer with Mechanical Resonators Arthur Safira, Jan Gieseler, Aaron Kabcenell, Shimon Kolkowitz, Dave Patterson, Alexander Zibrov, Jack Harris, Mikhail Lukin Nitrogen vacancy centers (NVs) are promising candidates for quantum computation, with room temperature optical spin readout and initialization, microwave manipulability, and weak coupling to the environment resulting in long spin coherence times. The major outstanding challenge involves engineering coherent interactions between the spin states of spatially separated NV centers. To address this challenge, we are working towards the experimental realization of mechanical spin transducers. We have successfully fabricated high quality factor (Q \textgreater 10$^{\mathrm{5}})$, doublyclamped silicon nitride mechanical resonators integrated with magnetic tips, and report on experimental progress towards achieving the coherent coupling of the motion of these resonators with the electronic spin states of individual NV centers under cryogenic conditions. Such a system is expected to provide a scalable platform for mediating effective interactions between isolated spin qubits. [Preview Abstract] 

D1.00093: Temperature Sensitivity of an Atomic Vapor CellBased DispersionEnhanced Optical Cavity Krishna Myneni, David D. Smith, Hongrok Chang, Heather A. Luckay Enhancement of the response of an optical cavity to a change in optical path length, through the use of an intracavity fastlight medium, has previously been demonstrated experimentally and described theoretically for an atomic vapor cell as the intracavity resonant absorber. This phenomenon may be used to enhance both the scale factor and sensitivity of an optical cavity mode to the change in path length, e.g. in gyroscopic applications. We study the temperature sensitivity of the onresonant scale factor enhancement, $S_0$, due to the thermal sensitivity of the lowerlevel atom density in an atomic vapor cell, specifically for the case of the ${}^{87}$Rb $D_2$ transition. A semiempirical model of the temperaturedependence of the absorption profile, characterized by two parameters, $\alpha_0(T)$ and $\Gamma_\alpha (T)$, allows the temperaturedependence of the cavity response, $S_0(T)$ and $dS_0/dT$ to be predicted over a range of temperature. We compare the predictions to experiment. Our model will be useful in determining the useful range for $S_0$, given the practical constraints on temperature stability for an atomic vapor cell. [Preview Abstract] 

D1.00094: Precision phase measurements with an SU(1,1) interferometer using 4wave mixing in hot Rb85 vapors Prasoon Gupta, Brian Anderson, Travis Horrom, Paul Lett Interferometry allows for the precision measurement of length and optical phase. Quantum entanglement of the optical state internal to the interferometer can help in achieving higher precision in phase measurement than is possible with classical light sources.\footnote{Phys.Rev.D 26,1817}\footnote{Phys.Rev.A 33,4033} In this context we are constructing an SU(1,1) interferometer$^3$ in order to perform precision measurement of optical phase. An SU(1,1) interferometer can be understood as a MachZehnder interferometer with the beam splitters replaced by a nonlinear gain medium which can generate entangled photons. The output depends on the relative phase shift provided to the photons inside the interferometer$.^3$\footnote{Phys.Rev.A 86,023844}\footnote{Nat Commun 5,3049} We use either vacuum or coherent beam seeds for the optical paths. Here we measure the error in our optical phase depending on the measurement of the number of photons at the outputs of the interferometer and compare it with the classical and Heisenberg limits. In future we also want to apply more sophisticated techniques of Bayesian analysis to our measurements to compute the error in optical phase estimation which could improve the sensitivity of phase estimation.\footnote{ISBN13: 9780124110113} [Preview Abstract] 

D1.00095: Developing a Parametric Downconversion Apparatus for SinglePhoton Experiments in Quantum Optics Stephen DiIorio We report our progress toward developing a parametric downconversion apparatus for studying singlephoton quantum optics in undergraduate laboratory classes, following the model of Galvez, et al. (Galvez, E. J., et al., Am. J. Phys. 73, 2 (2005)). We pump a beta barium borate (BBO) crystal with a 405nm diode laser to produce correlated pairs of singlephotons that we detect using avalanche photodiodes (APD). We can conduct coincidence and anticoincidence counts and a measurement of the degree of secondorder coherence with the apparatus, and we expect to report on single and biphoton interferometry experiments. [Preview Abstract] 

D1.00096: NEW LIGHT SOURCES, LASER TECHNOLOGY AND SHORT PULSE GENERATION 

D1.00097: Optoelectronic oscillator using an acoustooptic delay line Sin Hyuk Yim, Tae Hyun Kim, Sangkyung Lee, Hee Sook Roh, Kyu Min Shim We demonstrate an optoelectronic oscillator (OEO) based on an acoustooptic modulator (AOM). The free spectral range between the modes is a function of the total loop length of the OEO, which is dependent on the propagation time of the acoustic wave through the AOM. By using the huge difference in the magnitude between the speed of light and the acoustic velocity in the AOM, we can extend the effective loop length of the OEO up to 3.8 km. We have measured phase noise of the OEO. Further developments will be made by using a dualloop configuration. [Preview Abstract] 

D1.00098: Extending Double Optical Gating to the Midinfrared Timothy Gorman, Antoine Camper, Pierre Agostini, Louis DiMauro In the past decade there has been great interest in creating broadband isolated attosecond pulses (IAPs). Primarily these IAPs have been generated using Ti:Sapphire 800nm short pulses, namely through spatiotemporal gating with the attosecond lighthouse technique, amplitude gating, polarization gating, and double optical gating (DOG). Here we present theoretical calculations and experimental investigations into extending DOG to using a 2um driving wavelength, the benefits of which include extended harmonic cutoff and longer input driving pulse durations. It is proposed that broadband IAPs with cutoffs extending up to 250 eV can be generated in Argon by using \textgreater 30 fs pulses from the passivelyCEP stabilized 2um idler out of an optical parametric amplifier combined with a collinear DOG experimental setup. [Preview Abstract] 

D1.00099: ABSTRACT WITHDRAWN 

D1.00100: An ultrafast optics undergraduate advanced laboratory with a modelocked fiber laser Andrew Schaffer, Connor Fredrick, Chad Hoyt, Jason Jones We describe an ultrafast optics undergraduate advanced laboratory comprising a modelocked erbium fiber laser, autocorrelation measurements, and an external, freespace parallel grating dispersion compensation apparatus. The simple design of the stretched pulse laser uses nonlinear polarization rotation modelocking to produce pulses at a repetition rate of 55 MHz and average power of 5.5 mW. Interferometric and intensity autocorrelation measurements are made using a Michelson interferometer that takes advantage of the twophoton nonlinear response of a common silicon photodiode for the second order correlation between 1550 nm laser pulses. After a preamplifier and compression, pulse widths as narrow as 108 fs are measured at 17 mW average power. A detailed parts list includes previously owned and common components used by the telecommunications industry, which may decrease the cost of the lab to within reach of many undergraduate and graduate departments. We also describe progress toward a relatively lowcost optical frequency comb advanced laboratory. [Preview Abstract] 

D1.00101: Sensing aggregation in highly turbid plasmonic and nonplasmonic colloidal suspensions Rey Nann Mark Ducay, Nathan Philip, Jordan Boivin, Patrick Judge, Jason Berberich, Jonathan Scaffidi, Lalit Bali, Samir Bali We demonstrate a method for sensing the presence of aggregation in highly turbid aqueous suspensions of polystyrene and gold nanospheres. Aggregation is induced either by changing the pH or the ionic strength, by adding small, controlled amounts of an acid or base solution. The particle concentrations used are at least two orders of magnitude higher than previously reported. To the best of our knowledge, this is a first observation of aggregation in highly dense colloidal suspensions without any sample dilution or special sample preparation. [Preview Abstract] 

D1.00102: Subten nanosecond laser pulse shaping using lithium niobate modulators and a doublepassed tapered amplifier C.E. Rogers III, P.L. Gould We present progress on developing a laser pulse shaping system capable of generating pulses shorter than ten nanoseconds and frequency chirps of up to about 5 GHz in 2.5 ns. Shaped control of phase and amplitude on this timescale may prove useful for producing ultracold molecules [1] and controlling atomic hyperfine state populations [2]. The pulses are generated by passing 780 nm light from an external cavity diode laser through a fibercoupled lithium niobate (LN) phase modulator (PM) in series with an LN intensity modulator (IM). The modulators are driven with a singlechannel 8 GS/s arbitrary waveform generator configured with an RF delay line for quasitwo channel pulsed operation. The optical pulses are then amplified in a doublepass tapered amplifier (TA). The TA's intrinsic mode structure leads to an etalon effect that modulates the pulse amplitude during a frequency chirp. To reduce this unwanted effect, a compensating intensity modulation can be programmed onto the seed pulse. This work is supported by DOE.\\[4pt] [1] J. L. Carini, et al., Phys. Rev. A \textbf{87}, 011401(R), 2013.\newline [2] G. Liu, et al., Phys. Rev. A \textbf{89}, 041803(R), 2014. [Preview Abstract] 

D1.00103: On Exploration the speed of light and dark matter Yongquan Han Explain the three speed. 1) the radiation speed: refers to the speed of the hypothetical objects which doesn't radiate, denoted as C. 2) the object's rotation speed, denoted as v. refers to the radiation velocity of an object: 3) vector refers to speed and speed of the object's rotation of the radiation, denoted as U. Radiation velocity is a constant, the sun in the long period, the rotation speed is a constant speed of u$=$ $\sqrt {\mbox{c}^{2}+\mbox{v}^{2}} $, it is a constant. When the object's rotation velocity equal to the speed of light, the objects radiation speed of u$=$ $\sqrt 2 $C, the object is equal to the speed of light rotation, radiation ability is lower than the less than the speed of light rotation, the radiation area equal to the time it is 2 times the radiation area, that is to say, the radiation intensity is less than half of the original. We say that the state is the inflection point of special matter and dark matter state of the object. The clouds obscured the sun light, or less than half the sun rays, we cannot see the prototype of the sun,. When the object's rotation speed exceeding the speed of light, the same time, radiation range object is bigger, the radiation intensity is smaller. [Preview Abstract] 

D1.00104: Anomalous enhancement and suppression of ionization induced by an effective fewcycle pulse in the frequency domain David Foote, Yingda Lin, Wendell T. Hill, III In a recent set of coherent control experiments, an anomalous sinusoidal variation of the ionization yield was observed in Xe when ionized by a pairs of phaselocked, manycycle 800 nm pulses. Compared with the signal of a single transform limited pulse, both enhancement and suppression was possible, which depended on the temporal separation and relative phase of the pulses. In the time domain, the control can be viewed as a temporal Young's double slit experiment  two coherent electron wavepackets interfering. In the frequency domain, the photoelectron spectrum is given by the modulus squared of the Fourier transform of the field, which is a fewcycle squared sinusodial function. In analogy to a fewcycle pulse where the carrier phase dictates the ejection direction of rescattered electrons, enhancement (suppression) occurs when the effective carrier waveform is cos[ww0]$^2$ (sin[ww0]$^2$). The contrast decreased with increasing pulse separation and decreasing multiphoton order. Detailed results and a model simulation will be presented. [Preview Abstract] 

D1.00105: ABSTRACT WITHDRAWN 

D1.00106: TIMERESOLVED MOLECULAR DYNAMICS AND FEMTOCHEMISTRY 

D1.00107: Realtime Dynamics of Surface Photoreactions Probed with Ultrashort XUV Pulses Xinlong Li, Peng Zhao, Christopher Corder, Austin Polanco, Melanie Reber, Yuning Chen, Amanda Muraca, Matthew Kershis, Michael White, Thomas Allison High harmonic generation (HHG) and timeresolved photoelectron spectroscopy (TRPES) are wellestablished technique, broadly applicable for studying electronic and nuclear dynamics in real time. However, conventional HHG is typically limited to low repetition rates (\textless 100 kHz), hindering its applications. In our lab, we use cavity enhanced HHG to produce high repetitionrate (80 MHz) XUV ($\sim$ 40 eV) pulses. We make use of Ybfiberbased twostage chirped pulse amplification, producing NIR pulses with 80 MHz repetition rate, 150 fs duration and 70 W average power. In the subsequent enhancement cavity, pulses are coherently added and stored, leading to an intensity that is hundreds of times higher to achieve HHG with Argon gas. For surface experiments, this can help us keep the perpulse fluence low to avoid space charge effects. Our specific goal is uncovering the dynamics of the photoreactions on surfaces, focusing on bare titanina (TiO2) and titania surfaces which contain noble metal nanoparticles. [Preview Abstract] 

D1.00108: Probing calculated O$_2^{+}$ potential curves with an XUVIR pumpprobe experiment Philipp Coerlin, Andreas Fischer, Michael Schoenwald, Alexander Sperl, Tomoya Mizuno, Thomas Pfeifer, Robert Moshammer, Uwe Thumm We study dissociative photoionization of O$_2$ in a kinematically complete XUVIR pumpprobe experiment, preparing a vibrational wave packet in the potential of the binding O$_2^{+}$($a\,^4\Pi_u$) state by ionization with a single XUV photon. After a variable timedelay the wave packet is promoted to the repulsive O$_2^{+}$($f\,^4\Pi_g$) state by a weak IR probe pulse. Comparing the results of a coupledchannel simulation with the experimental kineticenergyrelease and quantumbeat spectra, we are able to discriminate between the adiabatic O$_2^{+}$ potentialenergy curves (PECs) calculated by Marian et al., Mol. Phys. 46, 779 (1982) and Magrakvelidze et al., Phys. Rev. A 86, 023402 (2012). The overall agreement between simulated and experimental results is good; however, not all features of the experimental spectra could be reproduced using these PECs. Using a Morse potential adjusted to the experimental data instead, most features of the experimental spectra are well reproduced by our simulation. This optimized Morse potential is remarkably similar to the theoretically predicted PECs, demonstrating the sensitivity of our experimental method to small changes in the shape of the binding potential. [Preview Abstract] 

D1.00109: Coulomb explosion imaging of bound and continuum nuclear wave packets in strongfield ionization of iodomethane Y. Malakar, M. Zohrabi, W.L. Pearson, B. Kaderiya, Kanaka Raju P., I. BenItzhak, D. Rolles, A. Rudenko As a prototypical polyatomic system with wellstudied photodissociation dynamics, the iodomethane molecule (CH$_{3}$I) has recently been used to test novel quantum control schemes [1], and to investigate charge transfer processes after Xray absorption [2]. These applications require a detailed understanding of CH$_{3}$I behavior in intense laser pulses. Here we present the results of a timeresolved Coulomb explosion imaging experiment that maps both, bound and dissociating nuclear wave packets in singly and doubly charged ionic states of CH$_{3}$I. Measuring energies and emission angles of coincident ionic fragments as a function of time delay between two 25 fs, 800 nm pump and probe pulses, we track the propagation of different dissociation pathways, vibrational motion of the molecule and its impulsive alignment. In particular, a periodic ($\sim$ 130 fs) feature in the delaydependent ion energy spectra can be assigned to CI stretching vibrations in the two lowest cationic states, and exhibits intriguing correlation with the oscillations observed in the laser pump / Xray probe experiment on charge transfer at LCLS [2]. [1] M.E. Coralles et al, Nature Chemistry 6, 785 (2014). [2] B. Erk et al, Science 345, 288 (2014). [Preview Abstract] 

D1.00110: Strongfield induced bond rearrangement and hydrogen migration in small hydrocarbons Yubaraj Malakar, Wright Lee Pearson, Artem Rudenko Imaging and control schemes for photoinduced structural rearrangement dynamics (isomerization, proton migration, H$_{2}$/H$_{3}$ elimination etc.) are of particular interest to ultrafast photochemistry. The strongfield regime offers a variety of possibilities to map these reactions (e.g., employing coincident momentumresolved ion spectroscopy), and to control them by exploiting fieldmodified or fieldinduced potentials. Here we report on a series of experiments that study bond rearrangement in small hydrocarbons (CH$_{4,\, }$C$_{2}$H$_{2}$, C$_{2}$H$_{4})$ irradiated by intense 800 nm laser pulses. We disentangle different fragmentation pathways and identify the isomerization channels by measuring coincident ion momentum patterns for two or threebody breakup channels. For C$_{2}$H$_{2}$ and C$_{2}$H$_{4}$ isomerization, we observe the evolution of kinetic energy release spectra with increasing laser pulse duration, which allows us to distinguish the isomerization pathways active within or after the pulse. We demonstrate that a significant (up to an order of magnitude) enhancement of C$_{2}$H$_{4}$ isomerization yield and H$^{3+}$ elimination from CH$_{4}$ for a given light intensity can be achieved with an increase in pulse duration from 25 to 200 fs. [Preview Abstract] 

D1.00111: Probing and Manipulating Ultrafast Dynamics in Carbon Dioxide Using Multicolor Vacuum Ultraviolet Pulses Travis Wright, Elio Champenois, James Cryan, Dipanwita Ray, Niranjan Shivaram, Felix Sturm, Dan Slaughter, Ali Belkacem A timeresolved study of ultrafast dynamics in carbon dioxide is presented. The singlet delta state is excited by a two photon 4.75 eV pump and has intersections with many states which can ultimately lead to neutral dissociation. Probing with 11 eV to the dissociative cationic C state, we measure a lower limit of approximately 200 fs for this neutral dissociation channel. Adding an additional and independently controlled third pulse of infrared photons (1.6 eV) is shown to affect the time dynamics in this manifold of lowest lying neutral states, altering the dissociation in the neutral. Velocity Map Imaging is used to resolve the kinetic energy release, total ion yield, and angular distributions of both the photoions and photoelectrons produced in this three pulse experiment. [Preview Abstract] 
(Author Not Attending)

D1.00112: LaserEnabled Interatomic Coulomb Decay (ICD) Dynamics in Ar Dimer Predrag Ranitovic, XiaoMin Tong, C. Hogle, L. Martin, K. Ueda, M.M. Murnane, H.C. Kapteyn We used XUV radiation in combination with an IR laser field to enable \textit{and }control Interatomic Coulomb Decay processes in Ar dimer. A hollow Ar dimer, with a 3s electron kickedout by a 36 eV XUV pulse, is a weakly bound molecular assembly, vibrating with a period of 300 fs. This 3s hole state decays radiatively since the ICD process is energetically forbidden. By adding the IR laser pulses, we can enable \textit{and/or} control the ICD process as we delay the probe IR pulses relative to the XUV pump pulse. We have studied these processes by utilizing CoulombExplosion imaging in a COLTRIMS geometry where we measured full 3D momenta of the coincident Ar$^{+}$ monomers coming from the same Ar dimer. By enabling the ICD process at different internuclear distances of the vibrating hollow Ar dimer, we open different CE channels with a distinctive signature in the measured kinetic energy releases. To the best of our knowledge this is the first work that demonstrates a timeresolved control over an ICD processes. [Preview Abstract] 

D1.00113: Exploring Ultrafast Molecular Dynamics using Photoelectron Spectra from UV/XUV PumpProbe Experiments Elio Champenois, James Cryan, Niranjan Shivaram, Travis Wright, Ali Belkacem The motion of atoms in molecules can drive electron dynamics via nonadiabatic couplings. In small molecules such as Ethylene, Carbon Dioxide, and Nitrophenol, this can lead to isomerization, electronic relaxation, or other timedependent effects following excitation from a bonding to an antibonding molecular orbital. To study these mechanisms, we use ultraviolet photons of various energies from a bright High Harmonic Generation source to first initiate dynamics and subsequently probe the system through ionization. We record the kinetic energy and angular distribution of the resultant photoelectrons using a Velocity Map Imaging spectrometer, allowing us to track the evolution of the electronic state. [Preview Abstract] 

D1.00114: VUV pump  infrared probe studies of molecular dissociation following stateselective photoexcitation Y. Malakar, B. Kaderiya, W.L. Pearson, Kanaka Raju P., Xiang Li, Wei Cao, I. BenItzhak, A. Rudenko, D. Trabert, F. Wilhelm Timeresolved measurements employing light sources based on highharmonics generation are typically performed using broadband pulses aiming at the shortest pulse duration achievable. This inherently results in a population of a superposition of states. In contrast, we employed $\sim$ 100 fs VUV pulses with a narrow bandwidth of $\sim$ 200meV (filtered by a grating pair), to achieve stateselective excitation. We used 11$^{th}$ harmonic pump (centered at 17.3 eV)  800 nm probe pulse sequence to trigger the dissociative ionization of O$_{2}$ and CO$_{2}$, which was characterized by energy and angleresolved photoion and photoelectron detection. While for the case of O$_{2}$ the data can be understood in terms of the (net) absorption of one and two 800 nm photons from the VUVexcited ionic state, the preliminary CO$_{2}$ results manifest rich dynamics, which surprisingly resembles the behavior observed in a recent experiment [1], where a comb of 11$^{th}$ to 17$^{th}$ harmonics was used. \\[4pt] [1] H. Timmers et al, Phys. Rev. Lett. 113, 113003 (2014). [Preview Abstract] 

D1.00115: Density Functional study of WignerSmith time delays in photoionization and photorecombination of argon Maia Magrakvelidze, Mohamed Madjet, Gopal Dixit, Misha Ivanov, Himadri Chakraborty We investigate quantum phases and WignerSmith time delays in photoionization and photorecombination of valence electrons of argon [1, 2] using KohnSham timedependent local density approximation (TDLDA) [3] with the Leeuwen and Baerends exchangecorrelation functional. Numerical results for the phases at respective 3p and 3s Cooper minima show opposite variations resulting from the correlation that is based on mutual couplings between 3p and 3s channels. Computed attosecond WignerSmith time delays show excellent agreements with two recent independent experiments on argon that measured the relative 3s3p time delay in photoionization [4] and the delay in 3p photorecombination [5]. \\[4pt] [1] Magrakvelidze et al. (in review);\\[0pt] [2] Dixit et al., PRL 111, 203003 (2013);\\[0pt] [3] Madjet et al., PRA 81, 013202 (2010);\\[0pt] [4] Kluender et al., PRL 106, 143002 (2011);\\[0pt] [5] Schoun et al., PRL 112, 153001 (2014). [Preview Abstract] 

D1.00116: Attosecond delay and angular asymmetry in plasmonic photoemission of C$_{60}$ T. Barillot, C. Cauchy, V. Loriot, C. Bordas, F. Lepine, PA. Hervieux, M. Gisselbrecht, P. Johnsson, J. Laksman, E. Mansson, S. Sorensen, S. Canton, J. Dahlstrom, M. Magrakvelidze, H. Chakraborty, G. Dixit, M. Madjet We present a theoryexperiment joint study of effects of the giant plasmon resonance of C$_{60}$ on photoionization angular asymmetry, phase and time delay. Phases of ionization amplitudes are utilized to compute WignerSmith delays and angular asymmetries of emissions from HOMO and HOMO1 levels in timedependent local density approximation (TDLDA) [1, 2], uncovering significant plasmon effects [3]. Electron momentum imaging spectroscopy is used to measure the photoelectron angular distribution asymmetry parameter at the plasmon that agreed well with TDLDA [3]. Preliminary results of our experiments using RABITT pumpprobe metrology show promise of attosecond measurements of plasmondriven delays to complement our predictions. * franck.lepine@univlyon1.fr ** himadri@nwmissouri.edu \\[4pt] [1] Madjet et al., JPB 41, 105101 (2008);\\[0pt] [2] Maurat et al., JPB 42, 165105 (2009);\\[0pt] [3] Barillot et al., (in review). [Preview Abstract] 

D1.00117: Photoionization of atoms confined in C$_{60}$ versus C$_{240}$: Giant enhancement and attosecond delay Maia Magrakvelidze, Kele Shi, Dylan Anstine, Himadri Chakraborty We investigate the effects of confinement and electron correlation on the photoemissions of noble gas atoms sequestered endohedrally in C$_{60}$ versus C$_{240}$. The timedependent local density approximation (TDLDA) method [1] with Leeuwen and Baerends (LB94) exchangecorrelation functional is employed. We study the moduli and phases of the photoionization dipole matrix elements involving atomictype as well as atomfullerene hybridtype levels of the molecules and extract associated cross sections and angleintegrated WignerSmith timedelays [2]. We examine the size effects of the molecular cage on the plasmonically enhanced strength of the atomic ionization [3]. Furthermore, the behavior of emission time delays in attoseconds, induced by this enhancement as well as by the confinementmodified atomic Cooper minima, as a function of fullerene size is scrutinized in detailed. \\[4pt] [1] Madjet et al., PRA 81, 013202 (2010);\\[0pt] [2] Dixit at al., PRL 111, 203003 (2013);\\[0pt] [3] Madjet et al., PRL 99, 243003 (2007). [Preview Abstract] 

D1.00118: Attosecond study of confinement in photoionization of xenon caged in C$_{60}$ Maia Magrakvelidze, Gopal Dixit, Mohamed Madjet, Himadri Chakraborty Effects of atomfullerene orbital hybridization and C$_{60}$ cavity on the attosecond time delay of the photoionization of Xe in the Xe@C$_{60}$ endohedral molecule are investigated using time dependent local density approximation (TDLDA) [1] augmented by the Leeuwen and Baerends exchangecorrelation functional. TDLDA WignerSmith delay is found to modify via three distinct mechanisms: (i) Screening (or antiscreening) of the atomic valence emission due to the plasmonic motions of C$_{60}$ charge cloud [2]; (ii) dynamical interactions [3] between Xe Cooper minima and C$_{60}$ cavity minima [4]; and (iii) confinement oscillations in the photoionization of inner 4d shell of Xe from the resonant formation of standing waves inside the cavity. The effects may be experimentally accessible by the so called RABITT metrology. \\[4pt] [1] Madjet et al., PRA 81, 013202 (2010);\\[0pt] [2] Madjet et al., PRL 99, 243003 (2007);\\[0pt] [3] Dixit et al., PRL 111, 203003 (2013); \\[0pt] [4] Magrakvelidze et al., arXiv:1409.2910 [physics.atmclus]. [Preview Abstract] 

D1.00119: IONATOM AND IONION COLLISIONS 

D1.00120: Charge Transfer in C$^{6+}$ Collisions with H and He T.G. Lee, M.S. Pindzola Charge transfer cross sections are calculated for C$^{6+}$ + H and C$^{6+}$ + He collisions using a timedependent closecoupling method in Cartesian coordinates. Capture cross sections into the $1s$, $2l(l=01)$, $3l(l=02)$, and $4l(l=03)$ subshells of C$^{5+}$ are found for projectile energies ranging from 5.0 keV/amu to 15.0 keV/amu. Comparisons are made with previous calculations and recent experiments. The atomic collision data will be used to better understand the interaction of solar wind ions with interplanetary atoms. [Preview Abstract] 

D1.00121: Merged beams studies for astrobiology Daniel Wolf Savin, Kenneth A. Miller, Aodh P. O'Connor, Nathalie de Ruette, Julia Stuetzel, Xavier Urbain The chain of chemical reactions leading towards life is thought to begin in molecular clouds when atomic carbon and oxygen react with H$_3^+$, leading to the formation of complex organic molecules and of water. Uncertainties in the rate coefficients for these reactions hinder our ability to understand the first links in the chemical chain leading towards life. Theory and experiment have yet to converge in either the magnitude or temperature dependence. We have developed a novel merged beam apparatus to study these reactions at the low collision energies relevant for molecular cloud studies. Photodetachment of atomic anion beams is used to produce beams of neutral C and O, each in their ground term as occurs in molecular clouds. The neutral beam is then merged with a velocity matched, copropagating H$_3^+$ beam. The merged beams method allows us to use fast beams (keV in the lab frame), which are easy to handle and monitor, while being able to achieve relative collision energies down to $\approx 10$ meV. Using the measured mergedbeams rate coefficient, we are able to extract cross sections that we can then convolve with a Maxwellian energy spread to generate a thermal rate coefficient for molecular cloud temperatures. Here we report recent results. [Preview Abstract] 

D1.00122: Differential cross sections for electron transfer, excitation, and elastic scattering in keVenergy collisions between protons and He$^+$ ions Thomas Winter Coupledstate differential cross sections are being determined for electron transfer, excitation, and elastic scattering in collisions between keVenergy protons and He$^{+}$ ions. Integrated cross sections for these and other collisions were recently reported.\footnote{T. G. Winter, Phys. Rev. A {\bf 87}, 032704 (2013).} Some differential cross sections were previously considered with smaller Sturmian bases as well as triplecenter bases\footnote{T. G. Winter, Phys. Rev. A {\bf 49}, 1767 (1994).} using an eikonal approach.\footnote{L. Wilets and S. J. Wallace, Phys. Rev. {\bf 69}, 84 (1968).} The impact parameter $\rho$ is now expressed in terms of the scattering angle for potential scattering with an impactparameterdependent effective nuclear charge corresponding to partial screening by an electron in the He$^{+}$ ground state. Integrating over the scattering angle, this formal transformation does yield the same total cross sections for excitation and electron transfer as when integrating directly over $\rho$. Differential cross sections obtained in this way are likely to be valid at least for elastic scattering when this is the dominant channel. [Preview Abstract] 

D1.00123: Protonhydrogen collision at cold temperatures Ming Li, Bo Gao We study the protonhydrogen collision in the energy range from 0 to 5 K where the hyperfine structure of the hydrogen atom becomes important. A proper multichannel treatment of the hyperfine structure is found to be crucial at cold temperatures compared to the elastic approximation traditionally used at higher temperatures. Both elastic and hyperfinechanging inelastic processes are investigated, using both a newly developed multichannel quantumdefect theory (MQDT) and the coupledchannel numerical method. Results from the two methods show excellent agreement with MQDT providing an efficient and basically analytic description of the protonhydrogen interaction throughout this energy range. We also discuss the validity of the elastic approximation and its relation to other methods. [Preview Abstract] 

D1.00124: Laser assisted charge transfer in the realm of cold collisions Alexander Petrov, Constantinos Makrides, Svetlana Kotochigova We study two colliding particles, Ca and Yb$^+$, which can undergo nonradiative chargeexchange transitions from the scattering continuum in the excited A$^2\Sigma^+$ state to the continuum of the ground X$^2\Sigma^+$ state. This reaction can be controlled by linearlypolarized laser radiation of frequency $\omega$, which is in the range of quasimolecular electronic energy separation. Using the dressedstate picture or the Floquet Ansatz we construct coupled timeindependent Schr\"odinger equations for the interatomic separation $R$. The mechanism of electromagnetic field control is based on an interplay between intramolecular couplings and moleculefield interactions. We show that laser field affects the chemical reaction through reversible modification of an effective Hamiltonian via either nonresonant temporal Stark shifts or resonant ``dipolar'' interactions, leading to both transient and cwlightinduced nonadiabatic charge transfer. We investigate these processes for various collision energies as well as over a wide range of laser intensities and frequencies. [Preview Abstract] 

D1.00125: Target electron ionization in Li$^{2+}$Li collisions: A multielectron perspective M.D. \'Spiewanowski, L. Guly\'as, M. Horbatsch, T. Kirchner The recent development of the magnetooptical trap reactionmicroscope has opened a new chapter for detailed investigations of chargedparticle collisions from alkali atoms. It was shown that energydifferential cross sections for ionization from the outershell in O$^{8+}$Li collisions at 1500 keV/amu can be readily explained with the singleactiveelectron approximation. Understanding of Kshell ionization, however, requires incorporating manyelectron effects. An ionizationexcitation process was found to play an important role [1]. We present a theoretical study of target electron removal in Li$^{2+}$Li collisions at 2290 keV/amu [2]. The results indicate that in outershell ionization a singleelectron process plays the dominant part. However, the Kshell ionization results are more difficult to interpret. On one hand, we find only weak contributions from multielectron processes. On the other hand, a large discrepancy between experimental and singleparticle theoretical results indicate that multielectron processes involving ionization from the outer shell may be important for a complete understanding of the process.\\[4pt] [1] T. Kirchner et al., Phys. Rev. A 89, 062702 (2014);\\[0pt] [2] M. D. \'{S}piewanowski et al., accepted for publication in J. Phys. Conf. Series (2015). [Preview Abstract] 

D1.00126: Local density probing of atomic gas via cold LiCa$^{+}$ inelastic collisions in an atomion hybrid system Ryoichi Saito, Shinsuke Haze, Munekazu Fujinaga, Kazuki Kyuno, Takashi Mukaiyama Ultracold atoms in a harmonic trap inevitably has an inhomogeneous density distribution, which makes an atomic gas an ensemble of atoms in different physical phases. Recent technical advances in the determination of local physical quantities in an atomic gas overcome this complexity and make it possible to directly compare experimental results with manybody theories of a homogeneous atomic gas. A lasercooled ion can be used as a highspatial resolution probe of physical quantities of an atomic gas. The spatial spread of an ion can be reduced to submicrons, which is even small enough for the application of the local probe of atoms in optical lattices. In our experiment, we constructed Li and Ca$^{+}$ ultracold hybrid system and observed inelastic collisions as a loss of ions. The inelastic collision is confirmed to be a chargeexchange process, whose rate depends linearly on the local atomic density. From the measurement of the rate of the chargeexchange, we can reproduce an atomic density profile. This is an important step toward a local probe of physical quantities of atoms with cold ions. In this presentation, we report on the observation of chargeexchange collisions between Li atom and Ca$^{+}$ ions, and discuss the feasibility of the ions as a probe of the atoms. [Preview Abstract] 

D1.00127: XRay Diagnostics of CUEBIT Highly Charged Ion Plasma Roshani Silwal, Amy Gall, Chad Sosolik, James Harriss, Endre Takacs Clemson University Electron Beam Ion Trap (CUEBIT) is one of the few EBIT facilities around the globe that produces highly charged ions by successive electron impact ionization. Ions are confined in the machine by the spacecharge of the electron beam, a 6 T magnetic field generated by a superconducting magnet, and the voltages applied to axial electrodes. The device is a small laboratory scale instrument for the study of the structure and emission of highly charged ions and the collisions of these ions with external targets. Along with the introduction of the facility including its structure and capabilities, we present an overview of various spectroscopic and imaging tools that allow the diagnosis of the high temperature ion cloud of the CUEBIT. Instruments include a crystal spectrometer, solidstate detectors, and pinhole imaging setup equipped with an xray CCD camera. Measurements of xray radiation from CUEBIT are used to investigate the fundamental properties of the highly charged ions and their interaction with the energetic electron beam. [Preview Abstract] 

D1.00128: Extended Opacity Tables with Higher TemperatureDensityFrequency Resolution Mark Schillaci, Chris Orban, Franck Delahaye, Marc Pinsonneault, Sultana Nahar, Anil Pradhan Theoretical models for plasma opacities underpin our understanding of radiation transport in many different astrophysical objects. These opacity models are also relevant to HEDP experiments such as ignition scale experiments on NIF. We present a significantly expanded set of opacity data from the widely utilized Opacity Project, and make these higher resolution data publicly available through OSU's portal with dropbox.com. This expanded data set is used to assess how accurate the interpolation of opacity data in temperaturedensityfrequency dimensions must be in order to adequately model the properties of most stellar types. These efforts are the beginning of a larger project to improve the theoretical opacity models in light of experimental results at the Sandia Zpinch showing that the measured opacity of Iron disagrees strongly with all current models. [Preview Abstract] 

D1.00129: ATOMATOM AND ATOMMOLECULE COLLISIONS 

D1.00130: Timeresolved UVIR pumpstimulated emission pump spectroscopy to probe the collisional dynamics of highly excited cesium vapor Salah Uddin MD, Phill Arndt, Burcin Bayram We have used a pumpstimulated emission pump spectroscopic technique to measure the collisional dynamics in the highly excited level of $^{133}Cs$ atomic vapor. Aligned $8p\,^2P_{3/2}$ cesium atoms were produced by a pump laser. A second laser, stimulated emission pump, promoted the population exclusively down to the $5d\,^2D_{5/2}$ level. The intensity of the $5d\,^2D_{5/2}\rightarrow 6s\,^2S_{1/2}$ cascade fluorescence at 852.12 nm was monitored. The linear polarization degree for the $6s\,^2S_{1/2}\rightarrow8p\,^2P_{3/2}\rightarrow5d\,^2S_{5/2}$ transition was measured in the presence of argon gas at various pressures. From the measurement, we obtained the collisional cross section (disalignment cross section) value in the $8p\,^2P_{3/2}$ level cesium. [Preview Abstract] 

D1.00131: Frequency Chirped Pulses at Large Detuning with an InjectionLocked Diode Laser for Atomic Physics Experiments Brian Kaufman, Anthony Limani, Kevin Teng, Martin Disla, John Dellatto, Tracy Paltoo, Matthew Wright We have built a laser system that allows us to generate a frequencychirped laser pulse at rapid modulation speeds ($\sim$ 100 MHz) with a large frequency offset. Laser light from an external cavity diode laser is passed through a lithium niobate electrooptical phase modulator (EOM). We drive the EOM with a $\sim$ 6 GHz signal whose frequency is itself modulated at speeds on the order of 100 MHz. This light is passed into an injectionlocked laser which is used to filter out all of the light except the frequencychirped $\pm$ 1 order by more than 30 dB. Using an RF switch, we are able to turn the injection locking on and off on a time scale faster than 20 ns. We are currently exploring using this system to adiabatically transfer atoms into an excited state. [Preview Abstract] 

D1.00132: Ultracold chemistry with alkalimetalrareearth molecules Constantinos Makrides, Jisha Hazra, Gagan Pradhan, Brian Kendrick, Thom\'{a}s Gonz\'{a}lezLezana, Balakrishnan Naduvalath, Alexander Petrov, Svetlana Kotochigova A first principles study of the dynamics of $^6$Li$(^2S)+^6$Li$^{174}$Yb$(^2\Sigma^+) \to ^6$Li$_2( ^1\Sigma^+)+^{174}$Yb$(^1S)$ reaction is presented at cold and ultracold temperatures. The computations involve determination and analytic fitting of a threedimensional potential energy surface for the Li$_2$Yb system and quantum dynamics calculations of varying complexities, ranging from exact quantum dynamics within the closecoupling scheme, to statistical quantum treatment, and universal models. It is demonstrated that the two simplified methods yield zerotemperature limiting reaction rate coefficients in reasonable agreement with the full closecoupling calculations. The effect of the threebody term in the interaction potential is explored by comparing quantum dynamics results from a pairwise potential that neglects the threebody term to that derived from the full interaction potential. Inclusion of the threebody term in the closecoupling calculations was found to reduce the limiting rate coefficients by a factor of two. [Preview Abstract] 

D1.00133: Jost function description of near threshold resonances I. Simbotin, D. Shu, R. C\^ot\'e The low energy behavior of cross sections for any scattering problem can be drastically affected by the presence of a resonance near the threshold. In this work, we show that any such strong dependence on energy can be accounted for in terms of the much simpler behavior of the Jost function. Although this is an old idea, see [E. J. Heller and W. P. Reinhardt, Phys.~Rev.~A \textbf{5}, 757 (1972)], and despite its advantages, it has not been employed widely. However, this method provides not only a theoretical tool for scattering problems in general, but also a convenient numerical approach in practice. [Preview Abstract] 

D1.00134: Rotationally inelastic collisions of He and Ar with NaK: Theory and Experiment K. Richter, T.J. Price, J. Jones, C. Faust, A.P. Hickman, J. Huennekens, R.F. Malenda, A.J. Ross, H. Harker, P. Crozet, R.C. Forrey Rotationally inelastic collisions of NaK $A\,^1\Sigma^+$ molecules with He and Ar are studied. At Lehigh, we use pumpprobe polarization labeling (PL) and laserinduced fluorescence (LIF) spectroscopy. At Lyon, Fourier transform (FT)resolved LIF spectra are recorded. In both cases, the pump laser excites a particular rovibrational level $A\,^1\Sigma^+$($v, J$). We observe strong direct lines corresponding to transitions from the ($v, J$) level pumped, and weak satellite lines corresponding to transitions from collisionallypopulated levels ($v, J^{\prime} = J + \Delta J$). The ratios of satellite to direct line intensities in LIF and PL yield population and orientation transfer information. A strong propensity for $\Delta J =$ even transitions is observed for both He and Ar perturbers. In the FT fluorescence experiment we also observe $v$changing collisions. {\it Ab initio} potential surface and scattering calculations are underway for collisions in the $A\,^1\Sigma^+$ and $X\,^1\Sigma^+$ states. For HeNaK we have calculated potential surfaces using GAMESS and carried out coupled channel scattering calculations of transfer of population, orientation, and alignment. Calculations of $v$changing collision cross sections are also in progress. [Preview Abstract] 

D1.00135: A neutral atommolecular ion collider: progress towards statetostate resolution in a chemical reaction MingFeng Tu, ShihKuang Tung, Brian Odom In our recent experiment [1], we demonstrated a scheme to prepare AlH$^{+}$ molecules in a single quantum state. This new development opens up new possibilities to study chemical reactions with statetostate resolution. Moving towards this new direction, we designed an experimental apparatus to study reactive interactions between neutral Rb atoms and AlH$^{+}$ molecules. Our hybrid machine consists of a Rb MOT and a spatially separated AlH$^{+}$ ion trap. A translatable dipole trap will be used to bring the Rb atoms to interact with the trapped AlH$^{+}$ molecules and will allow us to accurately control the collisional energies. Here we report our progress on building this experimental apparatus. \\[4pt] [1] C.Y. Lien, C.S. Seck, Y.W. Lin, J.H.V. Nguyen, D.A. Tabor, and B.C. Odom. Nat. Commun. 5, 4783 (2014). [Preview Abstract] 

D1.00136: Rovibrational inelastic scattering in the COH$_ 2$ complex R.C. Forrey, B. Yang, N. Balakrishnan, Peng Zhang, X. Wang, P.C. Stancil, J.M. Bowman Rovibrational inelastic collisional rate coefficients for the COH$_2$ system have significant application in interstellar astronomy. In an attempt to address this need, we present quantum coupledchannel calculations of rovibrational statetostate and total cross sections and rate coefficients. Full dimensional closecoupling (CC) and coupledstates (CS) approximation scattering calculations were carried out on a fulldimensional (6D) potential energy surface (PES), which was obtained using the highlevel CCSD(T)F12B method and fitted using an invariant polynomial approach in 6D. Pure statetostate rotational excitations from CO($v_1=0$, $j_1$=0, 1) were benchmarked with crossed molecular beam measurements. For rovibrational transitions, quenching cross sections and rate coefficients were calculated for the vibrational quenching of rovibrationally excited CO and H$_2$. The resulting data are compared with experimental results and previous calculations which used 4D PESs and various decoupling approximations, where available. Work is ongoing to extend the computations to highlying initial rovibrational levels though CC calculations in 6D require enormous computational resources. [Preview Abstract] 

D1.00137: Multichannel Quantum Defect Theory for Exotic Cold Collisions Brandon Ruzic, Jisha Hazra, Chris Greene, Balakrishnan Naduvalath, John Bohn Researchers have gained the ability to control an impressive variety of atoms and molecules at ultracold temperatures. However, scattering observables depend on a complicated set of internal states that cloud the interpretation of experiments and drastically increase computational time. We demonstrate two essential extensions of multichannel quantum defect theory (MQDT) that are required to describe these complex systems. On one hand, we include the anisotropic longrange interactions of dipolar atoms and molecules via a distorted wave approximation. On the other hand, we develop MQDT for chemically reactive molecular collisions, such as D+H$_2$ and the benchmark chemical reaction of F+H$_2$, with rovibrational quantum state resolution. [Preview Abstract] 

D1.00138: CN collisions with H$_2$ in fulldimension Benhui Yang, N. Balakrishnan, Xiaohong Wang, P. Stancil, J. Bowman, R. Forrey Rotational and vibrational rate coefficients of CN in collisions with H$_2$ are essential for modeling CN infrared spectra in interstellar gas. We report here fulldimensional potential energy surface (PES) and rovibrational scattering calculations for the CNH$_2$ collision system. A fulldimensional (6D) PES was calculated using the highlevel ab initio CCSD(T)F12B method. The invariant polynomial method was applied to fit the PES analytically in 6D. Quantum coupledchannel calculations of rotational excitation cross section of CN($j_1$=4) scattered by paraH$_2$($j_2$=0, 2) and orthoH$_2$ ($j_2$=1) were performed for collision energies ranging from 1.0 to 1500 cm$^{1}$. Statetostate rate coefficients of CN($j_1$=4) are computed for H$_2$ rotational states $j_2$=02. Comparison of the pure rotational cross sections and rate coefficients were made with previous available theoretical and experimental results. For the first time we present rovibrational quenching cross sections and rate coefficients of CN in collisions with H$_2$ on the new 6D PES. [Preview Abstract] 

D1.00139: ATOMIC AND MOLECULAR STRUCTURE AND PROPERTIES 

D1.00140: On the Lamb shift in neutral muonic helium Miron Amusia, Savely Karshenboim, Vladimir Ivanov The neutral muonic helium is an exotic atomic system consisting of an electron, muon and a nucleus. We consider it as a hydrogenlike atom with a compound nucleus that is also hydrogenlike system. There are a number of corrections to the Bohr energy levels, which all can be treated as contributions of generic hydrogenlike theory. While the form of those contributions is the same for all hydrogenlike atoms, their relative numerical importance differs from an atom to an atom. Here, the leading contribution to the electronic Lamb shift in the neutral muonic helium is found in a close analytic form together with the most important corrections. We believe that the Lamb shift in the neutral muonic hydrogen is measurable, at least through a measurement of the electronic 1$s$2$s $ transition. We present a theoretical prediction for the 1$s$2$s $ transitions with the uncertainty of 2 ppm (4 GHz), as well as for the 2$s$2$p $ Lamb shift with the uncertainty of 0.6GHz. [Preview Abstract] 

D1.00141: Relativistic allorder calculations of Th, Th$^{+}$ and Th$^{2+}$ atomic properties Ulyana Safronova, Marianna Safronova, Charles W. Clark Excitation energies, term designations, and $g$factors of Th, Th$^{+}$ and Th$^{2+}$ are determined using a relativistic hybrid configuration interaction (CI) + allorder approach that combines configuration interaction and linearized coupledcluster methods. The results are compared with other theory and experiment where available. Good agreement with experiment was found even for neutral Th owing to allorder treatment of the dominant correlation corrections and sufficient saturation of the configuration space. We find some ``vanishing'' $g$factors, similar to those known in lanthanide spectra. Reduced matrix elements, oscillator strengths, transition rates, and lifetimes are determined for Th$^{2+}$. To estimate the uncertainties of our results, we compared our values with the available experimental lifetimes for higher $5f7p\ ^3G_{4}$, $7s7p\ ^3P_{0}$, $7s7p\ ^3P_{1}$, and $6d7p\ ^3F_{4}$ levels of Th$^{2+}$. These calculations provide a benchmark test of the CI+allorder method for heavy systems with several valence electrons and yield recommended values for transition rates and lifetimes of Th$^{2+}$. [Preview Abstract] 

D1.00142: Quantum Interference due to Twostage Coupling of Electronic States in NaCs Carl Faust, Joshua Jones, John Huennekens We present new results from experimental studies of highlying electronic states of the NaCs molecule. The opticaloptical double resonance method is used to obtain Dopplerfree excitation spectra for several excited states. Selected data from the 11(0$^+$) and 12(0$^+$) high lying electronic states are used to obtain RydbergKleinRees (RKR) and Inverse Perturbation Approach (IPA) potential curves. Interactions between these two electronic states are evident in the patterns observed in the boundbound and boundfree fluorescence spectra. A twostage coupling model is presented to describe how the wavefunctions of the two states mix. The electronic parts of the wavefunction interact via spinorbit coupling, while the individual rovibrational levels interact via a second, different mechanism, likely nonadiabatic coupling. The interference between components of these mixed wavefunctions results in resolved fluorescence that is more complicated than one would predict from the pure electronic states. A modified version of the BCONT program (R. J. Le Roy, University of Waterloo) was used to simulate resolved fluorescence from both upper states. Parameters describing the twostage coupling were varied until simulations were able to adequately reproduce experimental spectra. [Preview Abstract] 

D1.00143: Complexscaling treatment for quantum entanglement in doubly excited helium atom ChienHao Lin, Yew Kam Ho Recently, we have investigated entanglement measures in natural atomic systems that involve two highly correlated indistinguishable spin1/2 fermions (electrons). Linear entropy and von Neumann entropy were calculated for spatial (electronelectron orbital) entanglement measures for ground and singly excited bound states in twoelectron atomic systems, such as He, H$^{\mathrm{}}$ and Ps$^{\mathrm{}}$ [1]. In our present work, we carry out an investigation on entanglement in doubly excited resonance states of helium. Since resonance states are lying in the scattering continuum, their energies are no longer bound by the variational theorem; we apply the complex scaling method [2] to solve the complex energy pole with which the resonance energy and resonance width are deduced. Hylleraastype wave functions are used to consider correlation effects. Once the wave function for a doubly excited state is obtained, we apply the Schmidt decomposition method [3] to calculate the linear entropy and von Neumann entropy for the doubly excited 2$s^{\mathrm{2}}$, 2$s$3$s$, 2$p^{\mathrm{2}}$, 3$s^{\mathrm{2}}$, and 3$p^{\mathrm{2}} \quad^{\mathrm{1}}S^{\mathrm{e}}$ resonance states in the helium atom. [1] Y.C. Lin, C.Y. Lin, and Y. K. Ho, \textit{Phys. Rev. A} \textbf{87}, 022316 (2013); Y.C. Lin and Y. K. Ho, \textit{Can, J. Phys}. (2014), accepted; C. H. Lin, Y.C. Lin, and Y. K. Ho, \textit{FewBody Syst.} \textbf{54}, 2147 (2013). [2] Y. K. Ho, \textit{Phys. Rept.} \textbf{99}, 1 (1983). [3] C. H. Lin and Y. K. Ho, \textit{FewBody Syst. }\textbf{55}, 1141 (2014); \textit{Phys. Lett. A }\textbf{378}, 2861 (2014). [Preview Abstract] 

D1.00144: Quantum entanglement of helium atom in highlying Rydberg states LiGuang Jiao, Y.K. Ho Quantum entanglement for identical particles in atomic systems and quantum dots has attracted considerable interest in recent years. With the successes of our group in accurately calculating the quantum entanglement (measured by von Neumann or the linear entropy) for the helium atom in ground and lowerlying excited states [1], we move on to the higherlying Rydberg states and concentrate on the asymptotic behavior of the entanglement in loosely bound states. By applying the Lowdin's canonical orthogonalization method to the Slatertype orbital configurationinteraction basis sets [2], we have obtained quite accurate wave functions for the 1$s$n$s$ $^{1}S^{\mathrm{e}}$ with n$=$1 to 15 and 2$s$n$s$ $^{3}S^{\mathrm{e}}$ states, with n$=$2 to 15, and from which entanglement entropies for such states are quantified by calculating the occupation numbers of the respective oneelectron reduced density matrix \textless i\textbar $\rho_{\mathrm{1}}$\textbar j\textgreater through a generalized eigenvalue problem. At the meeting, we will present our results and show the correlation between energies, effective quantum numbers, and entanglement for states in these Rydberg series.\\[4pt] [1] Y. C. Lin and Y. K. Ho, \textit{Phys. Rev. A} \textbf{87} (2013) 022316; \textit{Can. J. Phys.}, accepted (2014);\\[0pt] [2] L. G. Jiao and Y. K. Ho, \textit{Int. J. Quan. Chem.}, online published (2015). [Preview Abstract] 

D1.00145: Progress toward measuring the 6S$_{1/2}$ $\leftrightarrow$ 5D$_{3/2}$ magneticdipole transition moment in Ba$^{+}$ Spencer Williams, Anupriya Jayakumar, Matthew Hoffman, Boris Blinov, Norval Fortson We report the latest results from our effort to measure the magneticdipole transition moment (M1) between the $6S_{1/2}$ and $5D_{3/2}$ manifolds in Ba$^{+}$. We describe a new technique for calibrating viewport birefringence and how we will use it to enhance the M1 signal. To access the transition moment we use a variation of a previously proposed technique\footnote {S.R. Williams, \emph{ et. al.} Phys. Rev. A 88, 012515 (2013).} that allows us to isolate the magneticdipole coupling from the much larger electricquadrupole coupling in the transition rates between particular Zeeman sublevels. Knowledge of M1 is crucial for a paritynonconservation experiment in the ion where M1 will be a leading source of systematic errors. No measurement of this M1 has been made in Ba$^{+}$, however, there are three calculations that predict it to be 80$\times 10^{5} \mu_{B}$,\footnote{B.K. Sahoo, \emph{ et. al.} Phys. Rev. A 74, 062504 (2006). } 22$\times 10^{5} \mu_{B}$,\footnote{G.H. Gossel, \emph{ et. al.} Phys. Rev. A 88, 034501 (2013). } and 17$\times 10^{5} \mu_{B}$.\footnote{M. Safronova, Private communication} A precise measurement may help resolve this theoretical discrepancy which originates from their different estimations of manybody effects. [Preview Abstract] 

D1.00146: Quantum beat spectroscopy: Stimulated emission probe of hyperfine quantum beats in the atomic cesium Jacob McFarland, Phill Arndt, Burcin Bayram Measurements of hyperfine polarization quantum beats are used to determine the magnetic dipole ($A$) and electric quadrupole ($B$) coupling constants in the excited atomic Cs $8p\,^2P_{3/2}$ level. The experimental approach is a combination of pulsed optical pumping and timedelayed stimulatedemission probing of the excited level. From the measured evolution of the atomic linear polarization degree as a function of probe delay time, we determine the hyperfine coupling constants $A$ = 7.42(6) MHz and $B$ = 0.14(29) MHz. [Preview Abstract] 

D1.00147: Model Potentials for a C$_{60}$ Shell A.S. Baltenkov, S.T. Manson, A.Z. Msezane Radial square wells are commonly used to model the potential effects of the C$_{60}$ fullerene molecule [1]. The spatial distribution of electric charges forming such a square well potential has been analyzed. It is shown that this potential is created by two concentric spheres with a double layer of charges. This does not seem to be representative of the actual placement of the carbon nuclei in the molecule. A C$_{60}$ shell potential has been calculated under the more realistic assumption that it is formed by the averaged charge density of neutral carbon atoms. It is further demonstrated that the phenomenological potentials simulating the C$_{60}$ shell potential belong to a family of potentials with a nonflat bottom and nonparallel inner and outer potential walls. Two possible types of C$_{60}$ model potentials are proposed and their parameters have been calculated. However, experiment indicated that the potential does have identifiable (parallel) walls [2]. Thus, we are left with something of a conundrum. \\[4pt] [1] V. K. Dolmatov, Adv. Quantum Chem. \textbf{58 }13 (2009).\\[0pt] [2] A. R\"{u}del, R. Hentges, U. Becker, H. S. Chakraborty, M. E. Madjet and J. M. Rost, Phys. Rev. Lett. \textbf{89 }125503 (2002). [Preview Abstract] 

D1.00148: Unique energetic properties of Adenosine TriPhosphate in comparison to similar compounds using density functional theory Kevin Muraszko, Thomas Halloran, Svetlana Malinovskaya, Philip Leopold Adenosine TriPhosphate (ATP) is arguably the most critical compound to all life known on Earth, serving as the main energy transport and storage in cellular biology. Why in particular did nature ``choose'' ATP instead of a similar compound? We are seeking to answer this question by comparing the energetic properties of ATP to similar compounds. We discuss 3D models for ATP, variants of the molecule based on all of the separate nucleobases, and ATP's twin molecule Adenosine DiPhosphate. All calculations were done using Density Functional Theory. The results showed that purine compounds like Adenosine and Guanosine produce similar bond angles, making these viable unlike the other nucleobases. We have analyzed the chiral properties of ATP by comparing the groundstateenergies of ATPcis and ATPtrans and have shown that ATPcis is the more energetically favorable of the two. This is consistent with observations in nature. [Preview Abstract] 

D1.00149: Theoretical Studies of Dissociative Recombination of Electrons with SH$^+$ Ions D.O. Kashinski, O.E. Di Nallo, A.P. Hickman, J.Zs. Mezei, I.F. Schneider, D. Talbi We are investigating the dissociative recombination (DR) of electrons with the molecular ion SH$^+$. (The process is $e^ + \mathrm{SH}^+ \rightarrow \mathrm{S + H}$.) SH$^+$ is found in the interstellar medium (ISM), and little is known concerning its interstellar chemistry. The abundance of SH$^+$ in the ISM suggests that destruction processes, like DR, are inefficient. Understanding the role of DR as a destruction pathway for SH$^+$ will lead to more accurate astrophysical models. Large activespace multireference configuration interaction (MRCI) electronic structure calculations were performed to obtain excitedstate potential energy curves (PECs) for several values of SH separation. Excited Rydberg states have proven to be of importance. The block diagonalization method was used to disentangle interacting states, forming a diabatic representation of the PECs. Currently we are performing Multichannel Quantum Defect Theory (MQDT) dynamics calculations to obtain DR rates. The status of the work will be presented at the conference. [Preview Abstract] 

D1.00150: Theoretical Characterizaiton of Visual Signatures D.O. Kashinski, G.M. Chase, O.E. Di Nallo, A.N. Scales, D.L. VanderLey, E.F.C. Byrd We are investigating the accuracy of theoretical models used to predict the visible, ultraviolet, and infrared spectra, as well as other properties, of product materials ejected from the muzzle of currently fielded systems. Recent advances in solid propellants has made the management of muzzle signature (flash) a principle issue in weapons development across the calibers. \emph{A priori} prediction of the electromagnetic spectra of formulations will allow researchers to tailor blends that yield desired signatures and determine spectrographic detection ranges. Quantum chemistry methods at various levels of sophistication have been employed to optimize molecular geometries, compute unscaled vibrational frequencies, and determine the optical spectra of specific gasphase species. Electronic excitations are being computed using Time Dependent Density Functional Theory (TDDFT). A full statistical analysis and reliability assessment of computational results is currently underway. A comparison of theoretical results to experimental values found in the literature is used to assess any affects of functional choice and basis set on calculation accuracy. The status of this work will be presented at the conference. [Preview Abstract] 

D1.00151: The generalization of LuFano plot for multichannel atomic spectra with multiple ionization thresholds Xiang Gao, Rui Jin, XiaoYing Han, JiaMing Li Understanding the detailed dynamics of electronion interactions is of fundamental importance in the fields of astrophysics and so on. It's important to provide the related atomic data with accuracies determined. Using our modified Rmatrix code REigen [1], we can directly calculate the shortrange scattering matrices corresponding to the physical parameters associated with the multichannel quantum defect theory (MQDT) for both the discrete and continuous energy regions. Various physical quantities can then be derived from a straightforward application of the MQDT procedure. Through analytical continuation properties of shortrange scattering matrices, we demonstrated that the precisions of scattering calculations can be determined readily in a systematical way by using the LuFano plot [2] for Kr atom with two ionization thresholds [1]. We will show our studies of the graphical representations of the MQDT solutions of atomic spectra with multiple ionization thresholds, which is a generalization of LuFano plot [2] for the cases with two thresholds. In this way, we can determine the related scattering calculation precisions by using the spectroscopic data for general atoms with multiple ionization thresholds. We can also elucidate the intimate relations between the discrete energy levels and adjacent resonant autoionization spectra. [1] X. Gao and J. M. Li, Phys. Rev. A \textbf{89}, 022710 (2014). [2] C. M. Lee and K. T. Lu, Phys. Rev. A \textbf{8}, 1241 (1973). [Preview Abstract] 

D1.00152: Longitudinal Spin Relaxation in NitrogenVacancy Defect Centers in Diamond Pauli Kehayias, Andrey Jarmola, Dmitry Budker The negativelycharged nitrogenvacancy (NV$^$) color center in diamond is used in a range of applications, including quantum information and sensing. The longitudinal electronic spin relaxation time ($T_1$) of the NV groundstate magnetic sublevels is used for sensing paramagnetic spins, and $T_1$ represents a limitation to the NV spinnoise sensitivity. However, some fundamental aspects of $T_1$ relaxation remain a mystery, which we aim to resolve. We present the results of experimental NV $T_1$ studies done at the University of California Berkeley with collaborating laboratories. [Preview Abstract] 

D1.00153: ABSTRACT WITHDRAWN 

D1.00154: Modeling rubidium optical pumping in the intermediate buffergaspressure regime Dale Tupa, Timothy Gay Applications, such as a spinexchange polarized electron source,\footnote{Phys. Rev. A 88, 060701(R)} drive the need to understand the optical pumping process of Rb in the presence of 0.01  1.0 torr buffer gas. Despite the complexity of the systems, appropriate assumptions to simplify the calculations produce straightforward models that can be solved with programming languages such as Mathematica, or even with an Excel spreadsheet. These simplified equations adequately describe the system, as demonstrated by comparing the calculated results to experimental data that includes the effects of radiation trapping,\footnote{Phys. Rev. A 75, 023401} a spinreversal phenomenon,\footnote{Phys. Rev. A 82, 033408} and a method of measuring the polarization with a transverse optical probe.\footnote{Phys. Rev. A 86, 053416} [Preview Abstract] 

D1.00155: Suppression of Spin Noise in Diamond for improved Sensing and Imaging Erik Bauch, Junghyun Lee, Swati Singh, My Linh Pham, Keigo Arai, Ronald Walsworth Increasing the coherence time of nitrogen vacancy (NV) center spins in diamond is of great interest for quantum information, sensing and metrology applications. However, achieving long coherence times remains a challenge in dense samples, where the NV's $T_2$ is limited by electronic spinspin interaction of the nitrogen donors in the lattice. In these samples, nuclear spin impurities associated with the $^{13}$C isotopes can suppress the dominant nitrogen electronic spin bath by reducing the flipflop rates and enhancing the NV's coherence time. We investigate this spin bath suppression effect both experimentally and theoretically and provide a pathway to engineering high density NV samples with sufficiently long coherence times. [Preview Abstract] 

D1.00156: Computing Rydberg Electron Transport Rates via Classical Periodic Orbits Sulimon Sattari, Kevin Mitchell Electron transport properties of chaotic atomic systems are computable from classical periodic orbits. This technique allows for replacing a Monte Carlo simulation launching millions of orbits with a sum over tens or hundreds of properly chosen periodic orbits. Such computations are easiest to realize in sufficiently unstable systems dominated by a few short orbits. However, phase spaces exhibiting a mixture of chaos and regularity present a greater challenge, due to the rich dynamics in the vicinity of stable islands. Homotopic Lobe Dynamics (HLD) uses information encoded in the intersections of stable and unstable manifolds of a few orbits to compute almost all hyperbolic periodic orbits in a system. We compute the ionization rate for a Rydberg atom in parallel electric and magnetic fields. We apply HLD to compute orbits for parameters exhibiting both mixed and fully hyperbolic phase spaces. The ionization rate computed from periodic orbits converges exponentially to the true value as a function of highest period used. We then use periodic orbit continuation to accurately compute the ionization rate when the field strengths are perturbed. The ability to use periodic orbits in a mixed phase space could allow for studying transport in arbitrarily complex physical systems. [Preview Abstract] 

D1.00157: Helium PState Energies and Quantum Defect Analysis Travis Valdez, Ryan Peck, Gordon W.F. Drake Quantum defects provide a simple and accurate method of extending known atomic energies for low principal quantum number $n$ to higher $n$ up to the series limit, and including the scattering phase shift beyond. We will present new calculations of improved accuracy for the $1snp\;^1P$ and $^3P$ states of helium up to $n = 12$, based on variational calculations in Hylleraas coordinates. The results will be used to determine accurate values for the coefficients in the quantum defect expansion, $\delta = \delta_0 + \delta_2/n^{*2} + \delta_4/n^{*4} + \cdots$, where $n^* = n  \delta$. We will also test the usual assumption that only the even powers of $1/n^*$ need be included [1]. In addition, we will study the effectiveness of a unitary transformation in reducing the numerical linear dependence of the basis set for large basis sets. \\[4pt] [1] G.W.F. Drake, Adv.\ At.\ Mol.\ Opt.\ Phys.\ {\bf 32}, 93 (1994). [Preview Abstract] 

D1.00158: New Measurement of Singly Ionized Selenium Spectra by High Resolution Fourier Transform and Grating Spectroscopy Noman Hala, G. Nave, A. Kramida, T. Ahmad, S. Nahar, A. Pradhan We report new measurements of singly ionised selenium, an element of the iron group detected in nearly twice as many planetary nebulae as any other transiron element. We use the NIST 2~m UV/Vis/IR and FT700 UV/Vis Fourier transform spectrometers over the wavelength range of 2000~{\AA}  2.5~$\mu $m, supplemented in the lower wavelength region 3002400~{\AA} with grating spectra taken on a 3m normal incidence vacuum spectrograph. The analysis of Se II is being extended, covering the wide spectral region from UV to IR. From our investigation, we found serious inconsistency and incompleteness in the previously published results, where several levels were reported without any designation. The analysis is being revised and extended with the help of semiempirical quasirelativistic HartreeFock calculations, starting with the 4s$^{\mathrm{2}}$4p$^{\mathrm{3}}$ [4s$^{\mathrm{2}}$4p$^{\mathrm{2}}$(4d$+$5d$+$5s$+$6s)$+$4s4p$^{\mathrm{4}}$] transition array. Out of fiftytwo previously reported levels, we rejected thirteen and found several new level values. With the new measurements, we expect to observe transitions between 4s$^{\mathrm{2}}$4p$^{\mathrm{2}}$(4d$+$5s) and 4s$^{\mathrm{2}}$4p$^{\mathrm{2}}$(5p$+$4f), lying in the visible and IR region. A complete interpretation of the level system of both parities will be assisted by least squares fitted parametric calculations. In all, we have already classified about 450 observed lines involving 89 energy levels. [Preview Abstract] 

D1.00159: Polarization spectroscopy of the sodium dimer utilizing a tripleresonance technique in the presence of argon Phillip Arndt, Timothy Horton, Jacob McFarland, Burcin Bayram The collisional dynamics of molecular sodium in the $6^1\Sigma_g$ electronic state is under investigation using a triple resonance technique in the presence of argon. A continuous wave ring dye laser is used to populate specific rovibrational levels of the $A^1\Sigma_u$ electronic state. A pumpprobe technique is then employed where the pump laser populates the $6^1\Sigma_g$ state, and the probe laser dumps the population to the $B^1\Sigma_u$ state. From this level, fluorescence is detected as the system decays to the $X^1\Sigma_g$ state. We measure the polarization of this signal in the presence of various argon pressures. We will present our current work as well as the processes involved in the experiment. [Preview Abstract] 
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