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 Q1: Poster Session III (4:00 pm  6:00 pm) 
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Room: Convention Center Battelle South 

Q1.00001: NONLINEAR DYNAMICS AND OUTOFEQUILIBRIUM TRAPPED GASES 

Q1.00002: Numerical Calculations of Small to Large Numbers of Cold Fermions and Bosons in a 1D Double Well Potential Thomas Bergeman There have been many discussions of bosons in the TonksGirardeau (TG) regime in a quasi1D harmonic potential, but few that consider other potential forms. Experiments can now produce doublewell potentials by adding a Gaussian barrier to a harmonic potential in an array of 1D tubes, and a linear potential [1] can be used to initially displace the atom ensemble. Also, advanced techniques [2] can be used to load just a few atoms into a trap. To calculate the temporal evolution of such systems in a quasi1D double well potential, we use an ensemble of eigenfunctions with timedependent coefficients. Typically, we obtain complex diffraction patterns when the atom ensemble collides with the central potential barrier. We hope to extract effective tunneling rates as a function of the barrier height and width, of the initial velocity of the atom ensemble, and as a function of atom number, from the TG regime to the meanfield regime. \\ 1. J. Reeves, D. Schneble et al., New J. Phys. {\bf 16}, 065011 (2014). \\ 2. A. N. Wenz, S. Jochim et al., Science {\bf 342}, 457 (2013). \\ [Preview Abstract] 

Q1.00003: Onset of dissipation of BEC in shaking 2D Antidot optical lattices Toshiya Kinoshita, Kazuya Yamashita, Kouhei Hanasaki, Akihiro Ando, Hiroshi Kanemitsu, Ryosuke Goto We present a series of experiments with 87\textasciicircum Rb BEC loaded into 2D antidot optical lattices. This lattice has periodically arranged potential hills and energy minima which are connected to be meshlike structure. BEC in the lattice is considered to be well described as BEC with many holes when the barrier is slightly higher than chemical potential. We study onsets of dissipation of BEC by sinusoidally shaking antidot lattices. The dissipation is monitored by condensed fractions after thermalization. Below 0.5Erec barrier, we found a critical velocity vc, close to 0.5 recoil velocity. vc decrease down to $\sim$ 1mm/s at 2Erec and stay constant for much higher hills. The effects of dissipation also appear in interference patterns just after shaking. We present the details of our experiments. [Preview Abstract] 

Q1.00004: Coherent Dynamics in Dressed Optical Lattices Beyond the BornOppenheimer Approximation Jeremy Reeves, Ludwig Krinner, Mike Stewart, Arturo Pazmino, Dominik Schneble Usual treatments of matterwave diffraction assume that the zeropoint energy in the diffracting potential is much smaller than the gap between the dressed levels. However, in nearresonant weakdriving scenarios, zeropoint motion can mix the adiabatic dressed states, making the diffracting potentials highly nonadiabatic, such that the usual BornOppenheimer approximation for the external and internal degrees of freedom no longer applies. We model the dynamics of a matter wave in a microwavecoupled statedependent lattice in this regime, and quantify the importance of these effects on recent experiments. [Preview Abstract] 

Q1.00005: Investigating Cold Atom Transport in Optical Lattices and Ratchets Shan Zhong, Ethan Clements, Zach Pollock, Anthony Rapp, Preston Ross, Andrew Hachtel, Samir Bali We experimentally investigate cold atom transport in optical lattices and ratchets in an undergraduate setting using homebuilt laser and imaging systems. It is wellknown that the transport properties exhibited in these situations by ultracold atoms depart from the usual framework of BoltzmannGibbs statistical mechanics. We describe methods to quantify these departures by tracking the atomic momentum and spatial distribution, and measuring the ``dwell time'' and ``crossover time,'' respectively, in a particular well and between wells. [Preview Abstract] 

Q1.00006: A scalable method for measuring entanglement entropy of quantum manybody systems Eric Tai, Alex Lukin, Philipp Preiss, Matthew Rispoli, Ruichao Ma, Rajibul Islam, Markus Greiner Quantum manybody systems far from equilibrium are challenging to understand due to the spreading of quantum correlations among the constituents. Measuring the entanglement growth in such a system can serve to characterize the dynamical phases. We use high precision optical potentials in a quantum gas microscope to investigate quench dynamics and entanglement of a fewbody bosonic system. The entanglement entropy is directly estimated by interfering two identically prepared copies of the same dynamical state, in a manybody extension of the two particle HongOuMandel interference of bosons. This approach provides a versatile and scalable protocol for investigating the purity and entanglement growth of our system. [Preview Abstract] 

Q1.00007: COLD AND ULTRACOLD MOLECULES 

Q1.00008: Vibrational Cooling of Photoassociated Homonuclear Cold Molecules Henry Passagem, Paulo Ventura, Jonathan Tallant, Luis Marcassa In this work, we produce vibrationally cold homonuclear Rb molecules using spontaneous optical pumping. The vibrationally cooled molecules are produced in three steps. In the first step, we use a photoassociation laser to produce molecules in high vibrational levels of the singlet ground state. Then in a second step, a 50 W broadband laser at 1071 nm, which bandwidth is about 2 nm, is used to transfer the molecules to lower vibrational levels via optical pumping through the excited state. This process transfers the molecules from vibrational levels around $\nu \simeq $113 to a distribution of levels below $\nu =$35. The molecules can be further cooled using a broadband light source near 685 nm. In order to obtain such broadband source, we have used a 5mW superluminescent diode, which is amplified in a tapered amplifier using a double pass configuration. After the amplification, the spectrum is properly shaped and we end up with about 90 mW distributed in the 682 689 nm range. The final vibrational distribution is probed using resonanceenhanced multiphoton ionization with a pulsed dye laser near 670 nm operating at 4KHz. The results are presented and compared with theoretical simulations. This work was supported by Fapesp and INCTIQ. [Preview Abstract] 

Q1.00009: Quantum walk and localization dynamics of rotational excitations in disordered ensembles of polar molecules Tianrui Xu, Roman V. Krems We consider the dynamics of rotational excitations placed on a single molecule in a spatially disordered 1D, 2D and 3D molecular ensembles trapped in optical lattices. The disorder arises from incomplete populations of optical lattices with molecules. We show that for realistic experimental parameters this type of disorder leads to disorderinduced localization in 1D and 2D on a time scale $t \sim 1$ s. For 3D lattices with $55$ sites in each dimension and vacancy concentrations $\leq 90 \%$, the rotational excitations diffuse to the edges of the lattice. We observe that the diffusion has three distinct time scales. At short times, the rotational excitations diffuse as quantum particles expanding ballistically. At later times, the diffusion character changes to be the same as for the classical particles in Brownian motion. At still later times, the rotational excitations transition to a subdiffusive regime. The Brownianmotionlike regime can last as long as 200300 ms. We also examine the role of the longrange tunnelling amplitudes and find that it has little consequences for the dynamics of quantum particles in the diffusive regime but affects significantly the localization length of strongly localized particles. Reference: arXiv:1501.05063. [Preview Abstract] 

Q1.00010: Detecting and manipulating the rotational states of trapped polyatomic molecules Alexander Prehn, Rosa Gl\"{o}ckner, Martin Ibr\"{u}gger, Martin Zeppenfeld, Gerhard Rempe Many applications of cold and ultracold molecules require the ability to detect and manipulate internal states. Well established statedetection schemes (e.g. REMPI, LIF) often rely on the excitation of electronic states. However, this can lead to rapid predissociation, especially for many polyatomic molecules and thus limits their usefulness. Here we present an alternative detection method based on depletion of molecules in selected rotational states from an electric trap.\footnote{B.G.U. Englert {\it et al.}, Phys. Rev. Lett. {\bf 107}, 263003 (2011)} The narrow electricfield distribution of our trap\footnote{R. Gl\"{o}ckner {\it et al.}, arXiv:1411.7860 (2014)} allows us to spectroscopically address desired sets of states with microwave and infrared radiation and couple them to untrapped states, thus removing them from the trap and leading to a stateselective loss. Experimental data obtained with methyl fluoride (CH$_3$F) agrees nicely with rate equation models.\footnote{Gl\"{o}ckner {\it et al.}} Our method can be extended to allow for optical pumping of rotational states via a vibrational excitation. As we rely on generic properties of symmetric top molecules, application to other molecule species should be straightforward. [Preview Abstract] 

Q1.00011: Progress towards the laser cooling of the magnesium fluoride molecular beam Yong Xia, Dapeng Dai, Xingjia Li, Yanning Yin, Jianping Yin Though the laser cooling techniques that have been tremendously successful in producing ultracold atoms are difficult to apply to molecules, in the past few years, a new approach, laser cooling and trapping of diatomic molecules has become possible. We select magnesium fluoride (MgF) as a prototype molecule for laser cooling experiment. In order to compensate the changes of the Doppler shift during the longitudinal slowing of the molecular beam, we theoretically investigate the possibility of stimulated light force deceleration and cooling of the diatomic magnesium fluoride molecular beam with nearcycling transitions in the bichromatic standing light wave of high intensity which estimated by the twolevel optical Bloch equations. We also demonstrate a robust and versatile solution for locking the continuouswave Ti:sapphire tunable laser for applications in laser cooling of molecules which need linewidthnarrowed and frequencystabilized lasers. [Preview Abstract] 

Q1.00012: A cryogenic buffer gas cooled beam of BaH for molecular laser cooling and ultracold fragmentation Geoffrey Iwata, Marco G. Tarallo, Fabian Soerensen, Tanya Zelevinsky Laser cooled and trapped molecules promise many possibilities to explore a variety of fields such as manybody physics, quantum collisions and dissociation, and precision measurement. We report on an experiment for cooling and trapping barium monohydride (BaH) diatomic molecules. We present a cryogenic buffer gas cooling apparatus for producing a 4 K beam of BaH, and describe the laser cooling schemes necessary to load a molecular magnetooptical trap from that beam. Current progress includes identification of the cooling transitions in the BaH $B^2\Sigma \leftarrow X^2\Sigma$ manifold in laser ablated molecules and construction of the molecular beam. The large mass ratio of constituent atoms in BaH makes this system attractive for future studies of ultracold fragmentation, potentially resulting in samples of ultracold hydrogen atoms. [Preview Abstract] 

Q1.00013: Toward Triplet Ground State LiNa Molecules Alan Jamison, Timur Rvachov, Li Jing, Yijun Jiang, Martin Zwierlein, Wolfgang Ketterle We present progress toward creation of ultracold groundstate triplet LiNa molecules. This molecule is expected to have a long lifetime in the triplet ground state due to its fermionic nature, large rotational constant, and weak spinorbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. Our progress includes the first observation of triplet excited states in this molecule, achieved through photoassociation of ultracold mixtures of 6Li and Na. We compare experimental results to a variety of neardissociation expansions as well as ab initio potentials. [Preview Abstract] 

Q1.00014: Formation of ultracold polar ground state molecules via an optical process Olivier Dulieu, Dimitri Borsalino, Andrea Orban, Romain Vexiau, Beatriz LondonoFlorez, Anne Crubellier, Eliane Luc, Nadia BouloufaMaafa Based on spectroscopic studies available in the literature completed by accurate ab initio calculations for potentail energy curves, spinorbit couplings, and transition dipole moments, we investigate several optical coherent schemes to create ultracold bosonic and fermionic ultracold polar molecules in their absolute rovibrational ground level, starting from a weakly bound level of their electronic ground state manifold. The processes rely on the existence of convenient electronically excited states allowing an efficient stimulated Raman adiabatic transfer (STIRAP) of the level population. Illustrations are given for KRb and KCs. A model for the hyperfine structure of the excited molecular states is also presented. [Preview Abstract] 

Q1.00015: Prospect for the formation of a gas of ultracold polar NaRb molecules Goulven Qu\'em\'ener, Romain Vexiau, Gaoren Wang, Maxence Lepers, Eliane Luc, Nadia BouloufaMaafa, Olivier Dulieu, Dajun Wang We present a complete theoretical model for the formation of an ultracold gas of polar NaRb molecules, based on highprecision spectroscopic data completed with accurate quantum chemistry calculations. Weaklybound molecules are first created via a Feshbach resonance with main triplet character. The population is transfered down to the lowest rovibrational level of the ground state by a coherent STIRAP process. The efficiency of various paths via different electronicallyexcited molecular states is discussed in relation of the ongoing experimental implementation. [Preview Abstract] 

Q1.00016: Angularmomentum couplings in longrange Rydberg molecules David Anderson, Stephanie Miller, Georg Raithel We present results of a recent theoretical study of angularmomentum couplings in longrange diatomic Rydberg molecules formed between a rubidium Rydberg and $5S_{1/2}$ groundstate atom [1]. A Fermi model is used that takes into account all angularmomentum couplings comparable to the $e^+5S_{1/2}$ scattering interaction strength. The model includes S and Pwave singlet and triplet $e^+5S_{1/2}$ scattering, the finestructure of the Rydberg atom as well as the hyperfinestructure of the $5S_{1/2}$ atom. The effects of these couplings on the adiabatic molecular potentials are discussed. We calculate boundstate energies, lifetimes, and electric and magnetic dipole moments for the $^{87}$Rb$(nD_j+5S_{1/2})$ molecules in all potentials. The hyperfine structure gives rise to mixed singlettriplet potentials in both low and high$\ell$ molecular classes. These spinmixed potentials are deep enough to sustain bound states, which were recently observed in low$\ell$ Cs$_2$ molecules [2]. We also study the effects of the hyperfine structure on the deep $^3$S and $^3$P adiabatic molecular potentials in both Rb$_2$ and Cs$_2$ molecules.\\[4pt] [1] D. A. Anderson, S. A. Miller, G. Raithel, PRA (2014).\\[0pt] [2] H. Sa{\ss}mannshausen, F. Merkt, J. Deiglmayr, arXiv:1412.0846 (2014). [Preview Abstract] 

Q1.00017: New directions in direct laser cooling and trapping of diatomic molecules Matthew Steinecker, Daniel McCarron, Eric Norrgard, Eustace Edwards, David DeMille In recent years, tremendous progress has been made in laser cooling and trapping of molecules. With the achievement of a magnetooptical trap (MOT) for the diatomic molecule SrF,\footnote{J. F. Barry \textit{et al.}, \textit{Nature} \textbf{512}, 286289 (2014).} a range of novel experiments employing ultracold molecules may be within reach. Here we present planned improvements to our SrF MOT apparatus, including plans for more efficient MOT loading, subDoppler cooling, loading into a conservative trap, and cotrapping of atoms. These and other improvements should allow increases in trapped molecule number, lifetime, and phasespace density. We illustrate some of the experiments that will be enabled by these improvements, such as studies of inelastic and reactive atommolecule collisions at ultracold temperatures and investigations of sympathetic and evaporative cooling of SrF. [Preview Abstract] 

Q1.00018: Interactions between Rydberg atoms and ultracold polar molecules Maitreyi Jayaseelan, Marek Haruza, Nicholas P. Bigelow We investigate dipolar interactions arising in a hybrid system containing both ultracold polar molecules and atomic Rydberg states. Ultracold NaCs molecules are produced by photoassociation from laser cooled mixtures of sodium and cesium atoms and detected through resonant multiphoton ionization (REMPI). Rydberg atoms with large dipole moments are excited in the atomic cloud using a multiphoton process and detected via fieldionization. We look for evidence of the interactions in the observed spectra. [Preview Abstract] 

Q1.00019: HighResolution Spectroscopy of LongRange Molecular States of $^{85}$Rb$_2$ Ryan Carollo, Yoann Bruneau, Edward Eyler, Phillip Gould, William Stwalley We present analysis of low$n$ longrange molecular states in $^{85}$Rb$_2$, and additional highresolution spectra. Our process excites a photoassociation resonance in the $1 \, (0_g^)$ state which decays to $v''=35$ and 36 of the $a \, ^3 \Sigma _u^+$ state and to the continuum. These bound molecules are excited via a single photon to target states near the $5s + 7p$ asymptote by a frequencydoubled pulseampli?ed CW laser with narrow linewidth, under 200 MHz. The longrange portion of the bonding potential is formed by the scattering interaction of the Rydberg electron of a perturbed $7p$ atom scattering from a nearby groundstate atom, in the same manner as trilobite states. We use timeofflight to selectively measure molecular ions, which are formed via autoionization. This technique gives a two ordersofmagnitude improvement in linewidth over our previous excitation method, which was done by a broader linewidth conventional pulsed laser as reported in Ref. [1]. This work is supported by the NSF and AFOSR.\\[4pt] [1] M. A. Bellos \textit{et al.}, Phys. Rev. Lett. \textbf{111}, 053001 (2013) [Preview Abstract] 

Q1.00020: Cooling polar NaCs molecules in an electrostatic trap Marek Haruza, Maitreyi Jayaseelan, Nicholas P. Bigelow We present our scheme for creating an ultracold and dense sample of polar NaCs molecules. The molecules are photoassociated from laser cooled atoms and held in an electrostatic trap in their vibrational ground state and the lowest trappable rotational states. The trap depth dependance on the rotational quantum numbers can be exploited to cool the motion of the molecules by optical pumping between rotational levels.\footnote{Zeppenfeld, M. et al., Nature 491, 570573 (2012)} [Preview Abstract] 

Q1.00021: Towards Fluorescence Imaging of single SiO+ Patrick Stollenwerk, YenWei Lin, Brian Odom Working to generalize the techniques of atomic ion trapping to molecules, it is clear that the ability to image molecules is a fundamental requisite for such a goal. In our lab, we are interested in precision spectroscopy of SiO+ for measuring timevarying fundamental constants. We have been developing techniques for coherent control of trapped SiO+. We load the trap via laser ablation and subsequent 2+1 REMPI of SiO, and then optically pump SiO+ into its ground rotational state by driving the B:$\Sigma$ $\leftarrow$ X:$\Sigma$ band, which has nearly diagonal vibrational overlap. We use a broadband light source to drive multiple rotational cooling transitions simultaneously and avoid rotational heating transitions by using pulseshaping to modify its spectrum. We probe the ground state of SiO+ using laserinduced fluorescence. With vibrational repumping, excitation of single SiO+ within the BX (00) band produces 10$^{3}$ fluorescence photons over 1 ms, though there are uncertainties due to relaxation through the lowlying A:$\Pi$ state. These photons are projected onto an EMCCD, forming images of single SiO+. We will then study coherent control of SiO+'s rotation and perform precision spectroscopy with ultracold SiO+ by fluorescence imaging. [Preview Abstract] 

Q1.00022: Quantum Logic Spectroscopy of State Prepared AlH$^+$: Current Progress Mark Kokish, Matthew Dietrich, Christopher Seck, Brian Odom Recently demonstrated broadband rotational optical cooling of the aluminum monohydride ion (AlH$^+$) by our group\footnote{C.Y. Lien, C. M. Seck, Y.W. Lin, J. H. V. Nguyen, D. A. Tabor, and B. C. Odom, Nat. Commun. \textbf{5}, 4783 (2014).} has provided an efficient tool for molecular ion internal state preparation, a prerequisite for molecular quantum logic spectroscopy (mQLS). Motional ground state cooling of the molecular and atomic ion pair will be achieved by continuous Raman sideband cooling and stimulated rapid adiabatic passage (STIRAP) sideband cooling. We will present recent progress on this experiment including the molecular ion source, the state preparation scheme, and motional ground state preparation in the singleionscale trap. [Preview Abstract] 

Q1.00023: Feshbach and Photoassociation Resonances in an Ultracold LithiumYtterbium Mixture Richard Roy, Rajendra Shrestha, Alaina Green, Subhadeep Gupta Magnetic Feshbach resonances have allowed great success in the production of ultracold diatomic molecules from bialkali mixtures, but have so far eluded observation in mixtures of alkali and alkalineearthlike atoms. Inelastic collisional properties of ultracold atomic systems exhibit resonant behavior in the vicinity of such resonances, providing a detection signature. We study magnetic field dependent inelastic effects via atom loss spectroscopy in an ultracold heteronuclear mixture of alkali $^6$Li in the ground state and alkalineearthlike $^{174}$Yb in an excited electronic metastable state ($^3P_2$, $m_J = ?1$). We observe a variation of the interspecies inelastic twobody rate coefficient by nearly one order of magnitude over a 100 ? 520 G magnetic field range. By comparing to abinitio calculations we link our observations to interspecies Feshbach resonances arising from anisotropic interactions in this novel collisional system. Furthermore, we present photoassocation (PA) spectroscopy of $^6$Li and multiple isotopes of Yb using the Li D line (671 nm), working towards all optical coherent production of ground state LiYb molecules in a 3 dimensional optical lattice. [Preview Abstract] 

Q1.00024: Fermionic Ground State Molecules NaK with Strong Dipolar Interactions Jee Woo Park, Jennifer Schloss, Zoe Yan, Huanqian Loh, Sebastian Will, Martin Zwierlein $^{23}$Na$^{40}$K is a fermionic molecule that is especially well suited for this purpose. In the rovibrational ground state, NaK molecules are chemically stable and possess a large electric dipole moment of 2.72 Debye. The poster will report on our progress at MIT that recently led us to the creation of the first dipolar ground state molecules of NaK, covering the formation of Feshbach molecules, spectroscopic investigation of the molecular structure of NaK as well as the successful coherent twophoton transfer of NaK to the absolute ground state. These advances bring the exploration of novel states of matter in strongly dipolar quantum matter within experimental reach. [Preview Abstract] 

Q1.00025: Excitedstate spectroscopy for producing ultracold groundstate NaRb molecule Dajun Wang, Bing Zhu, Mingyang Guo, Xiaoke Li, Bo Lu, Fudong Wang, Xin Ye, Romain Vexiau, Eliane Luc, Nadia BouloufaMaafa, Olivier Dulieu We report a joint experimental and theoretical investigation on the excited states of NaRb molecule. In particular, we focus on the A$^1\Sigma^+$/b$^3\Pi$ admixture which is a promising intermediate state for transferring weaklybound NaRb Feshbach molecules to the $v$ = 0 level of the X$^1\Sigma^+$ state. Based on RKR potentials obtained from conventional molecular spectroscopy [1], we identified several levels which satisfy the requirements for efficient twophoton population transfer. Starting from a pure sample of NaRb Feshbach molecules, we have experimentally observed most of these levels. The detailed characterization of these levels, including their transition strengths and singlet/triplet mixing ratios, as well as searching of the $v$ = 0 level of the X$^1\Sigma^+$ state with twophoton AutlerTownes spectroscopy, are well underway. [Preview Abstract] 

Q1.00026: DEGENERATE FERMI GASES 

Q1.00027: SpinPolarized Fermi Gases in 1D, 3D, and Crossover Regimes Jacob A. Fry, Melissa C. Revelle, Ben A. Olsen, Randall G. Hulet We report recent results on mapping the superfluid transition as a function of atomic interaction and global spin polarization in a twocomponent, 3D gas of fermionic lithium. The atomic interactions are controlled using a Feshbach resonance to tune between the strongly interacting BEC regime and the weakly interacting BCS regime. Previously, a 3D gas was found to have an unpolarized superfluid core that is enclosed by polarized shells.\footnote{G. B. Partridge et al., Science 311, 503 (2006); Y. Shin et al., Phys. Rev. Lett. 97, 030401 (2006)} By applying a 2D optical lattice we confine our gas in onedimensional tubes. In this 1D gas, in contrast to the 3D gas, we found a partially polarized superfluid core and either fully polarized or fully paired wings depending on the overall spin polarization.\footnote{Y.A. Liao et al., Nature 467, 567 (2010).} In the current experiment, we have mapped the phase diagram of the 1D/3D crossover by increasing the intertube coupling. The exotic superfluid state, FFLO, is predicted to occupy a large portion of the phase diagram in the crossover regime, making it an ideal location in parameter space for its detection.\footnote{M. Parish et al., PRL, 99, 250403 (2007).} [Preview Abstract] 

Q1.00028: BCSBEC crossover and quantum phase transition in an ultracold Fermi gas under spinorbit coupling Fan Wu, Ren Zhang, TianShu Deng, Wei Zhang, Wei Yi, GuangCan Guo In this work, we study the BCSBEC crossover and quantum phase transition in a Fermi gas under Rashba spinorbit coupling close to a Feshbach resonance. By adopting a twochannel model, we take into account of the closed channel molecules, and show that combined with spinorbit coupling, a finite background scattering in the open channel can lead to two branches of solution for both the twobody and the manybody ground states. The branching of the twobody bound state solution originates from the avoided crossing between bound states in the open and the closed channels, respectively. For the manybody states, we identify a quantum phase transition in the upper branch regardless of the sign of the background scattering length, which is in clear contrast to the case without spinorbit coupling. For systems with negative background scattering length in particular, we show that the bound state in the open channel, and hence the quantum phase transition in the upper branch, are induced by spinorbit coupling. We then characterize the critical detuning of the quantum phase transition for both positive and negative background scattering lengths, and demonstrate the optimal parameters for the critical point to be probed experimentally. [Preview Abstract] 

Q1.00029: Low noise optical lattices for a Li6 Fermi gas microscope Anton Mazurenko, Maxwell Parsons, Christie Chiu, Florian Huber, Sebastian Blatt, Markus Greiner We report on recent progress towards singlesite resolved imaging of fermions in an optical lattice. Fermionic 6Li atoms are trapped in an optical lattice 10 $\mu$m below a highquality reference surface in the image plane of a high resolution (NA 0.85) imaging system. We have created a highly intensitystable optical lattice whose depth remains adjustable over three orders of magnitude. The high optical resolution enables a band mapping technique that allows detection of less than 1000 atoms in the ground band of the lattice. We use this technique to measure the decay of the radial ground band population and find lifetimes up to 70 seconds, limited by spontaneous scattering of lattice light. [Preview Abstract] 

Q1.00030: Topological superradiance in a degenerate Fermi gas JianSong Pan, XiongJun Liu, Wei Zhang, Wei Yi, GuangCan Guo We predict the existence of a topological superradiant state in a twocomponent degenerate Fermi gas in a cavity. The superradiant light generation in the transversely driven cavity mode induces a cavityassisted spinorbit coupling in the system and opens a bulk gap at half filling. This mechanism can simultaneously drive a topological phase transition in the system, yielding a topological superradiant state. We map out the steadystate phase diagram of the system in the presence of an effective Zeeman field, and identify a critical tetracritical point beyond which the topological and the conventional superraidiant phase boundaries separate. We propose to detect the topological phase transition based on its signatures in either the momentum distribution of the atoms or in the cavity photon occupation. [Preview Abstract] 

Q1.00031: Solitonic Excitations in Fermionic Superfluids and Progress towards Fermi Gas in Uniform Potential Mark Ku, Biswaroop Mukherjee, Elmer GuardadoSanchez, Zhenjie Yan, Parth Patel, Tarik Yefsah, Julian Struck, Martin Zwierlein We follow the evolution of a superfluid Fermi gas of $^6$Li atoms following a onesided $\pi$ phase imprint. Via tomographic imaging, we observe the formation of a planar dark soliton, and its subsequent snaking and decay into a vortex ring. The latter eventually breaks at the boundary of the superfluid, finally leaving behind a single, remnant solitonic vortex. The nodal surface is directly imaged and reveals its decay into a vortex ring via a puncture of the initial soliton plane. At intermediate stages we find evidence for more exotic structures resembling $\Phi$solitons. The observed evolution of the nodal surface represents dynamics that occurs at the length scale of the interparticle spacing, thus providing new experimental input for microscopic theories of strongly correlated fermions. We also report on the trapping of fermionic atoms of $^6$Li in a quasihomogenous alloptical potential, and discuss progress towards directly observing the momentum distribution of the fermions in a box. This new tool offers the possibility to quantitatively study Fermi gases at finite temperature and in the presence of spinimbalance, with unprecedented accuracy. [Preview Abstract] 

Q1.00032: VORTICES AND EXCITATIONS IN DEGENERATE QUANTUM GASES 

Q1.00033: Dissipative Dynamics of a Corotating Vortex Pair in a BoseEinstein Condensate Woo Jin Kwon, Geol Moon, Sang Won Seo, Minseok Kim, Moosong Lee, Jeong Ho Han, Yongil Shin We report on the longtime evolution of a corotating vortex pair in a highly oblate BoseEinstein Condensate at finite temperature. We generate a doubly charged vortex in a condensate by a phase imprinting method using a magnetic quadrupole field and measure the temporal evolution of the intervortex distance between corotating vortices. We find that the vortex separation monotonically increases over the hold time and its increasing rate is almost linearly proportional to the temperature of the system. We discuss the thermal damping on the vortex motion in a condensate. [Preview Abstract] 

Q1.00034: Construction of a new apparatus to study 2D superfluid dynamics in BECs Zach Newman, Jessica Doehrmann, Brian P. Anderson We are in the process of constructing a new apparatus at the University of Arizona with the intent of studying twodimensional superfluid dynamics, quantum turbulence, and vortex dynamics in highly oblate BoseEinstein condensates. The trap geometries used in such experiments enable the application of high resolution imaging methods that permit direct, in situ detection of vortices and wave phenomena in BECs. In this poster, we describe our design of a new apparatus aimed specifically at studying 2D superfluid phenomena, discuss technical challenges, and present progress towards the completion of our new apparatus. [Preview Abstract] 

Q1.00035: Stroboscopic \textit{in situ} detection of 2D superfluid dynamics in BECs Joseph Lowney, Kali Wilson, Brian P. Anderson BoseEinstein condensates (BECs) serve as an attractive medium for the study of quantum turbulence. Of particular interest is the ability of a BEC to sustain quantized vortices and solitons, which are central to our understanding of superfluid dynamics. Further studies of such dynamics would be greatly aided by minimally destructive \emph{in situ} detection of these microscopic density features. We demonstrate, discuss, and compare multiple methods of stroboscopic \emph{in situ} detection of 2D vortex distributions and superfluid wave phenomena in single component rubidium87 BECs. [Preview Abstract] 

Q1.00036: Superfluid Atomtronic Circuits Stephen Eckel, Fred Jendrzejewski, Avinash Kumar, Mark Edwards, Gretchen Campbell We present studies of superfluid atom circuit using a toroidal BoseEinstein Condensate (BEC). Just as a current in a superconducting circuit will flow forever, if a current is created in our superfluid circuit, the flow will not decay as long as the current is below a critical value. A repulsive optical barrier across one side of the torus creates a tunable weak link in the condensate circuit and can be used to control the current around the loop. Using a second BEC as a phase reference, we have developed techniques to read out the phase around the ring and current flowing in the ring. These techniques allow us to measure the currentphase relationship of our weak link, a single function characterizes the superfluid properties of the weak link. We can also insert two weak links that move through the ring in opposite directions. In this case, we observe resistive flow when the current exceeds the critical current, and can measure the currentvoltage relationship of our weak link. Lastly, we have studied the dynamics of persistent current decay in the system and temperature. These studies allow us to characterize the primary circuit component in our system, our weak link. [Preview Abstract] 

Q1.00037: Imprinting Multiple Spin Textures Simultaneously onto a Spinor BEC Joseph D. Murphree, Justin T. Schultz, Azure Hansen, Nicholas P. Bigelow Recent theoretical results have fueled interest in the interactions between complex spin textures in BECs such as coreless vortices, skyrmions, and monopoles. We present a method of using a coherent multiphoton Raman process to imprint these intricate textures to a ${}^{87}$Rb BEC. A spatial light modulator is capable of encoding dense spatiallydependent phase and amplitude textures such as higherorder LG modes and multiple singularities. The relative phase and amplitude profile of the beam are transferred to the condensate. This optical method allows the creation of multiple spin textures simultaneously to study their interactions and evolution. [Preview Abstract] 

Q1.00038: NonAbelian and 1/3 Fractional Vortices in Spin2 BoseEinstein condensates Azure Hansen, Justin T. Schultz, Nicholas P. Bigelow We present the creation of nonAbelian and 1/3 fractional vortices in a BoseEinstein condensate by a multistep stimulated optical Raman interaction that relies on beams carrying orbital angular momentum. The spin2 manifold of ${}^{87}$Rb supports complex topological structures due to the symmetry of the spinor wavefunction. A wavefunction that has a tetrahedral symmetry is especially interesting as multicomponent coreless vortices have 1/3 and 2/3 fractional topological charge. Such vortices are nonAbelian in nature, a property that manifests in their collision dynamics. Additionally, this spin texture corresponds to the configuration of the cyclic phase, which has neither ferromagnetic nor antiferromagnetic interactions. By observing the temporal evolution of these spin textures we can determine the ground state nature of spin2 ${}^{87}$Rb. [Preview Abstract] 

Q1.00039: ATOMIC MAGNETOMETERS AND SENSORS 

Q1.00040: Vectorial BellBloom atomic magnetometer using spin procession modulation Haichao Huang, Xuyang Hu, Haifeng Dong We present an experimental study of a vectorial BellBloom atomic magnetometer, which can measure two transverse magnetic fields and the total magnetic field at the same time. The light scheme is the same with the detection part in spin comagnetometer of Princeton university [1], where a bias field is added perpendicular to the pumping light and a probe light is added parallel to the bias field. When there is transverse magnetic field, the probe light will be modulated by the spin procession. As there is a phase difference of $\rm\pi/2$ between the x transverse field and y transverse field, we obtain the two transverse magnetic fields signal through the inphase and outofphase of a lockin amplifier. The total field is measured using resonance of the pumping light. Once the output signal is feedbacked to the coil, the bias field is locked to a constant value, and the transverse magnetic fields are locked to zero. In this way we obtain the threedimensional magnetic fields by the current in the coils. The dynamic range can be adjusted through the bias field, so this method can be used both in the magnetic shield and in the geomagnetic field range. \\[4pt] [1] D. Sheng, A. Kabcenell, and M. V. Romalis, Physical Review Letters 113, 163002 (2014). [Preview Abstract] 

Q1.00041: Pulse pumping high spatial resolution atomic magnetic microscopy Xuyang Hu, Haichao Huang, Lin Chen, Haifeng Dong Atom vapor magnetometer is currently the most sensitive magnetometer with the fundamental sensitivity of $\rm 0.012fT\cdot cm^{3}\cdot Hz^{\frac{1}{2}}$ and a measured sensitivity of $\rm 0.16fT\cdot Hz^{\frac{1}{2}}$ with a measurement volume of $\rm 0.45 cm^3$[1]. However, the spatial resolution is limited to millimeter scale even with the buffer gas because of the atom diffusion. We present a way to limit atom diffusion range and improve the spatial resolution by using short pulse pumping and CCD detector. The diffusion model and spinexchange relaxation time are used to calculate theoretically the relation between the spatial resolution and the magnetic sensitivity, which shows that sensitivityresolution product of the atomic magnetic microscopy (MM) is smaller than that of other MMs, such as scanning SQUID MM, NV diamond MM and BEC MM. The pulse pumping is generated using Photodigm DBR 180TS laser which can output a short pulse light of 300ns with a power of 180mW. The magnetic image is obtained from the laser spot images received by a Manta G145 NIR CCD. \\[4pt] [1] H. B. Dang, A. C. Maloof, and M. V. Romalis, Applied Physics Letters 97, 151110 (2010). [Preview Abstract] 

Q1.00042: Progress on a $^3$He$^{129}$Xe comagnetometer Mark Limes, Dong Sheng, Michael Romalis We report our recent progress on a $^3$He$^{129}$Xe comagnetometer using Rb readout. Previous iterations employed a Ramsey scheme with Rb used for intial spin polarization and for detection of only the initial and final phases of the two noble gas species that precess ``inthedark.'' Our current scheme attempts a continuous detection of the noble gas nuclei, which we've shown to increase shottoshot SNR over the pulsed scheme. Our technique mitigates the large difference of Fermicontact shifts on the precession frequencies of the noble gases due to polarized Rb by making the average Rb polarization zero with respect to the noble gases. This averaging is accomplished by applying Rb $\pi$ pulses and simultaneously pumping with $\sigma_+/\sigma_$ light with a fast repetition rate. The $^3$He$^{129}$Xe comagnetometer has many potential applications for precision measurements, including nuclear spin gyroscopes and searches for spingravity coupling. [Preview Abstract] 

Q1.00043: Synchronously pumped nuclear magnetic oscillator Anna Korver, Daniel Thrasher, Michael Bulatowicz, Thad Walker We present progress towards a synchronously pumped nuclear magnetic oscillator. Alkali frequency shifts and quadrupole shifts are the dominant systematic effects in dual Xe isotope comagnetometers. By synchronously pumping the Xe nuclei using spinexchange with an oscillating Rb polarization, the Rb and Xe spins precess transverse to the longitudinal bias field. This configuration is predicted to be insensitive to first order quadrupole interactions and alkali spinexchange frequency shifts. A key feature that allows coprecession of the Rb and Xe spins, despite a $\sim 1000$ fold ratio of their gyromagnetic ratios, is to apply the bias field in the form of a sequence of Rb 2$\pi$ pulses whose repetition frequency is equal to the Rb Larmor frequency \footnote{A. Korver, R. Wyllie, B. Lancor, and T. G. Walker, PRL {\bf111}, 043002 (2013).}. The 2$\pi$ pulses result in an effective Rb magnetic moment of zero, while the Xe precession depends only on the time average of the pulsed field amplitude. Polarization modulation of the pumping light at the Xe NMR frequency allows coprecession of the Rb and Xe spins. We will present our preliminary experimental studies of this new approach to NMR of spinexchange pumped Xe. [Preview Abstract] 

Q1.00044: Nanoscale Sensing with Nitrogen Vacancy Centers Elana Urbach, Igor Lovchinsky, Alex Sushkov, Hongkun Park, Mikhail Lukin In the last several decades Magnetic resonance imaging (MRI) has emerged as a powerful tool in science and technology. Conventional MRI technology, however, relies on measuring magnetic fields from a large (macroscopic) number of molecules, for example tissues in specific areas of the brain. Extending these techniques to the nanoscale could enable revolutionary advances in the physical, biological and medical sciences. Here we report on recent progress in using NitrogenVacancy (NV) centers in diamond to detect small numbers of nuclear spins in biological molecules. In particular, we have demonstrated detection of single proteins attached to the diamond surface. [Preview Abstract] 

Q1.00045: Measuring the Axion's CPviolating Couplings Junyi Lee, Michael Romalis Axions, which were first proposed in 1977 to explain the strong CP problem in QCD, have also became well motivated candidates for dark matter whose discovery would have farreaching consequences. We describe an experiment to measure the CPviolating axion coupling constant $g_p g_s$ with both the neutron and electron using a $^3$HeK atomic comagnetometer and a 200 kg source mass. It will enable us to surpass, for the first time in a laboratory experiment, the current tightest constraints on $g^N_p g^N_s$ derived by Raffelt\footnote{G. Raffelt, Phys. Rev. D \textbf{86}, 015001 (2012).} from astrophysical observations by an order of magnitude. With an expected sensitivity of $g^N_p g^N_s \sim 6 \times 10^{33}$, we would also exceed the current tightest laboratory constraints on $g^N_p g^N_s$ at large distances from Youdin \emph{et. al}\footnote{A. N. Youdin, D. Krause, Jr., K. Jagannathan, and L. R. Hunter, Phys. Rev. Lett. \textbf{77}, 11 (1996).} by 3 orders of magnitude. [Preview Abstract] 

Q1.00046: Nuclear Magnetic Resonance Gyroscope Michael Larsen, Michael Bulatowicz, Philip Clark, Robert Griffith, James Mirijanian, James Pavell The Nuclear Magnetic Resonance Gyroscope (NMRG) is being developed by the Northrop Grumman Corporation (NGC). Cold and hot atom interferometer based gyroscopes have suffered from Size, Weight, and Power (SWaP) challenges and limits in bandwidth, scale factor stability, dead time, high rotation rate, vibration, and acceleration. NMRG utilizes the fixed precession rate of a nuclear spin in a constant magnetic field as a reference for determining rotation, providing continuous measurement, high bandwidth, stable scale factor, high rotation rate measurement, and low sensitivity to vibration and acceleration in a low SWaP package. The sensitivity to vibration has been partially tested and demonstrates no measured sensitivity within error bars. Real time closed loop implementation of the sensor significantly decreases environmental and systematic sensitivities and supports a compact and low power digital signal processing and control system. Therefore, the NMRG technology holds great promise for navigation grade performance in a low cost SWaP package. The poster will describe the history, operation, and design of the NMRG. General performance results will also be presented along with recent vibration test results. [Preview Abstract] 

Q1.00047: Atomic Gradiometers for Fetal Magnetocardiography Ibrahim Sulai, Zack Deland, Colin Wahl, Michael Bulatowicz, Ron Wakai, Thad Walker We present results on development of $^{87}\mathrm{Rb}$ atomic magnetometers configured as magnetic field gradiometers for fetal Magnetocardiography (fMCG). Operating in the Spin Exchange Relaxation Free (SERF) regime, the magnetometers have a sensitivity $\sim 1 \; \mathrm{fT} / \sqrt{\mathrm{Hz}}$. Magnetic field gradient measurements significantly reduce the interference of uniform background fields. In fMCG applications, the field from the mother's heart is one such background and cannot be passively shielded. We report schemes for implementing such gradiometers along with recent fMCG measurements. This work is supported by the National Institutes of Health. [Preview Abstract] 

Q1.00048: Magnetoencephalography with Optically Pumped Atomic Magnetometers Peter Schwindt, Anthony Colombo, YuanYu Jau, Tony Carter, Christopher Berry, Amber Young, Jim McKay, Michael Weisend We are working to develop a 36channel array of optically pumped atomic magnetometers (AMs) to perform magnetoencephalography (MEG) with the goal of localizing magnetic sources within the human brain. The 36channel array will consist of nine 4channel sensor modules where the channels within each sensor will be spaced by 18 mm and each sensor will cover a 40 mm by 40 mm area of the head. In a previous 4channel AM prototype, we demonstrated the measurement of evoked responses in both the auditory and somatosensory cortexes. This prototype had a 5 fT/Hz$^{1/2}$ sensitivity. In the current version of the AM under development we are maintaining the previous sensitivity while implementing several improvements, including increasing the bandwidth from 20 Hz to more than 100 Hz, reducing the separation of the active volume of the AM from exterior of the sensor from 25 mm to 10 mm or less, and reducing the active sensor volume by a factor \textgreater 10 to $\sim$15 mm$^{3}$. We will present results on the performance of our most recent AM prototype and progress toward developing a complete MEG system including a personsized magnetic shield to provide a lownoise magnetic environment for MEG measurements. [Preview Abstract] 

Q1.00049: Towards magnetic imaging of neurons using NV diamond John Barry, Matthew Turner, David Glenn, Yuyu Song, Ronald Walsworth Magnetic field imaging based on optically detected magnetic resonances (ODMR) in NV diamond offers an unmatched combination of sensitivity, resolution and fieldofview. For certain biological applications NV diamond imaging is particularly useful; in contrast to traditional fluorescent markers, NV diamond imaging is labelfree and does not suffer from bleaching. Additionally the solidstate nature of NV diamond imaging allows for various fast modulation techniques to be employed to increase the signaltonoise ratio. Here we present progress towards creating an NV diamond imager with sensitivity and resolution appropriate for imaging neural activity within a living neural network. When integrating over our detector, we demonstrate a DC magnetic field sensitivity of better than 50 pT/Hz$^{1/2}$, which we demonstrate is suitable for detecting the action potentials in invertebrate giants axons. [Preview Abstract] 

Q1.00050: Nanoscale NMR and MRI with NV centers in diamond Emma Rosenfeld, Linh Pham, Chinmay Belthangady, Stephen DeVience, Paola Cappellaro, Mikhail Lukin, Ronald Walsworth We investigate a new technique for detecting nanoscale volumes of nuclear spins using shallow nitrogenvacancy (NV) centers in diamond and dark electronic spins at the diamondair interface. We apply dressedstate schemes to resonantly couple these dark electronic spins with optically accessible NV spins, thus taking advantage of the close proximity of the dark electronic spins to nuclear spins at the diamond surface in order to significantly enhance the sensitivity and reduce the detection volume of diamondbased nanoscale nuclear magnetic resonance (NMR) measurements. The improvements in detection afforded by this technique may enable sensing of single nuclear spins and NMR spectroscopy of single molecules. [Preview Abstract] 

Q1.00051: Optimizing the sensitivity of an NVdiamond magnetometer Matthew Turner, David Le Sage, Ronald Walsworth The nitrogenvacancy (NV) color center in diamond promises to be an extremely useful tool for precise optical magnetometry. Individual NV centers can function as atomicscale magnetometers and more sensitive magnetometry can be achieved by averaging the optical signal from a dense ensemble of NV centers. We discuss current state of the art magnetic sensitivities that have been achieved with a compact NVensemble magnetometer head. This magnetometer utilizes the optical waveguide properties of the diamond chip to achieve improved photon collection efficiency [1], and achieves improved performance compared with previous demonstrations by taking advantage of improved diamond sample engineering and readout electronics. These ongoing efforts suggest that with additional optimization, the sensitivity of NV magnetometers may soon approach the sensitivities achieved by the best existing magnetometer technologies, with the added practical advantages of being a compact, solidstate, roomtemperature device. \\[4pt] [1] D. Le Sage et al., Phys. Rev. B, 85, 121202(R) (2012) [Preview Abstract] 

Q1.00052: Onedimensional rings with barriers: a Luttinger liquid approach to precision measurement Stephen Ragole, Jacob Taylor Recent experiments [1] have realized ring shaped traps for ultracold atoms in which the atoms can be manipulated in several interesting ways. Here, we consider 1D ring system with a moving weak barrier within the framework of Luttinger liquid theory. We find that classical theory suggests high precision sensors can be constructed from these systems; we extend these results into the quantum regime. \\[4pt] [1] Wright, K., et al. Driving phase slips in a superfluid atom circuit with a rotating weak link. Phys. Rev. Lett. 110, 025302~(2013) [Preview Abstract] 

Q1.00053: ELECTRICDIPOLE SEARCHES AND TESTS OF FUNDAMENTAL SYMMETRIES 

Q1.00054: Theoretical study of heavyatom molecules to search for physics beyond the Standard model A.N. Petrov, L.V. Skripnikov, A.D. Kudashov, N.S. Mosyagin, A.V. Titov The goal of the report is to review our latest studies for heavyatom diatomics  ThO, RaO, RaF, PbF  which are of practical interest to search the T, Podd effects. Particular attention is devoted to the $H^{3}\Delta_{1\, }$ state of ThO [1, 2]. Combination of the spin precession measurement of ThO [3] with the calculated E$_{eff}$ (ThO) [1] leads to the most rigid limit on $e$EDM:, \textbar d$_{e}$\textbar \textless 8.7 $\times$ 10$^{29}$e$\cdot$cm. This is more than one order of magnitude better than other limits obtained. The knowledge of the gfactor dependence on electric fields is important for understanding possible systematic effects. Our study of the gfactors for $H^{3}\Delta_{1\, }$has shown that the J $=$ 2 rotational state should be even more robust against a number of systematic errors compared to J $=$ 1 [2]. [1] L. V. Skripnikov, A. N. Petrov, and A. V. Titov, JCP Communication, \textbf{139}, 221103 (2013) [2] A.N. Petrov, L.V. Skripnikov, A.V. Titov, N.R. Hutzler, P.W. Hess, \quad B.R. O'Leary, B. Spaun, D. DeMille, G. Gabrielse, and J.M. Doyle, \textit{Phys. Rev. A} \textbf{89}, 062505 (2014) [3] J. Baron, W. C. Campbell, D. DeMille, \textit{et al.} (ACME Collab.), \textit{Science} \textbf{343}, 269 (2014) [Preview Abstract] 

Q1.00055: Advances in the Francium Trapping Facility at TRIUMF J. Zhang, M.J. Kossin, L.A. Orozco, R. Collister, K.L. Shiells, G. Gwinner, M. Tandecki, A. Gorelov, J.A. Behr, M.R. Pearson, E. Gomez, S. Aubin, Y. Zhao We report the current status of the Francium Trapping Facility (FTF) at TRIUMF. We have successfully commissioned the science chamber of the FTF by demonstrating transfer of Fr atoms from the capture MOT to the science chamber, where weakinteraction experiments on Fr will be performed. The modular design of the science chamber allows for microwave studies of the nuclear anapole moment and optical studies of the weakcharge of the nucleus using atomic parity nonconservation. The 46.5 GHz microwave cavity, necessary for the anapole measurements in $^{210}$Fr, uses patterned aluminum on glassblanks to control the transmission of the mirrors. This design enables Q factors $>$ 40,000 in a FabryPerot configuration with mirrors separated by 12.5 cm. [Preview Abstract] 

Q1.00056: Approach to a permanent electron electric dipole moment search using cold atoms in an optical lattice Cheng Tang, Teng Zhang, David Weiss We present our progress towards measuring the electron EDM using lasercooled cesium and rubidium atoms trapped in a one dimensional optical lattice. To date, we have collected Cs atoms in two parallel 1D optical lattices that thread three glass electric field plates in a region of wellshielded magnetic fields. As a precursor to the EDM measurement, we have performed a variant of a Hanle effect measurement and used it to study the vector light shifts due to the cavitybuilt up lattice beams. This gives us a very high sensitivity to the absolute linear polarization of the light, which we have demonstrated to be as good as $\sim 10^{8}$ in fractional power. [Preview Abstract] 

Q1.00057: Systematics in a measurement of the electron's electric dipole moment using trapped molecular ions Matt Grau, Kevin Cossel, William Cairncross, Dan Gresh, Yan Zhou, Jun Ye, Eric Cornell A precision measurement of the electron's electric dipole moment (EDM) has important implications for physics beyond the Standard Model. Trapped molecular ions offer high sensitivity in such an experiment because of the large effective electric fields and long coherence times that are possible. Our experiment uses Ramsey spectroscopy of HfF$^+$ ions in a linear RF trap with rotating bias fields, achieving coherence times beyond 1 second for 1000 trapped ions. Compared to other electron EDM experiments that use molecular beams, we will be sensitive to a different class of systematic errors. In this work we investigate systematic errors arising from all fields involved in the experiment, including the trapping and polarizing electric fields, magnetic field gradients, and motional effects such as geometric phases. [Preview Abstract] 

Q1.00058: HYBRID QUANTUM SYSTEMS 

Q1.00059: Progress Towards Ion Trap Piezo Coupling K. Wright, K.G. Johnson, K. Collins, C. Monroe We report our current experimental progress towards coupling a macroscopic piezoelectric element to an ion. Current progress is being made using a fourrod Paul trap and a 1mm cube piezo made of PZT. By tuning the secular frequency of a trapped Yb $^{171}$ ion near the resonant motional eigenmode of the piezo, we should see an increase in the coupling between the two objects. We hope to see this coupling through observation of a peak in the ion heating rate as a function of ion secular frequency and distance to the piezo. [Preview Abstract] 

Q1.00060: Hybrid Quantum Optomechanics with Graphene Nanoresonators Airlia Shaffer, Ajay K. Bhat, Yogesh Sharad Patil, Sunil Bhave, Mukund Vengalattore We report on the realization of a hybrid quantum system consisting of a graphene nanoresonator coupled to an ultracold spin ensemble. This work is motivated by the large quantum nonlinearities inherent to graphene resonators, as well as the strong atomresonator coupling due to their commensurate mass ratio. We fabricate micromechanical suspended graphene membrane resonators and study their properties, both through spectroscopic and interferometric imaging. With dark field images, we relate the nonlinear intermode coupling in graphene to the quality factors of the modes. This work provides a foundation for the studies of entanglement between a macroscopic graphene membrane and an auxiliary quantum system of ultracold atoms. Additionally, such graphene resonators can be used for force, position, and mass sensing in the quantum limit. [Preview Abstract] 

Q1.00061: BECCryostat Interface: A Novel Platform for Hybrid Quantum Systems Aditya Date, Yogesh Sharad Patil, Keith Schwab, Mukund Vengalattore We present our experimental progress towards the implementation of a unique BECcryostat interface. This apparatus allows for the control and manipulation of ultracold atoms in close proximity to cryogenic surfaces. Such a system enables us to realize a hybrid quantum system consisting of a BEC strongly coupled magnetically to an ultrahigh Q mechanical resonator, thus enabling precise atomic sensing of mechanical motion [1]. Furthermore, the unprecedented sensitivities afforded by our atomic system open avenues to surface studies of correlated electronic systems at cryogenic temperatures.\\[4pt] [1] S. K. Steinke \em et al.\em\ PRA 84, 023841 [Preview Abstract] 

Q1.00062: Controlling Mechanical Dissipation through Phononic Bandgap Substrates Laura Chang, Srivatsan Chakram, Yogesh Sharad Patil, Mukund Vengalattore One of the fundamental challenges for the quantum control of mechanical systems is the realization of resonators with exceptionally low dissipation, through appropriate material choice and resonator and substrate design. Stoichiometric silicon nitride membrane resonators have in recent years emerged as an ultralow loss mechanical platform. In such resonators, we have demonstrated mechanical quality factors as high as $50\times 10^6$ and $f \times Q$ products of $1\times 10^{14}$ Hz, with radiation loss to the the supporting substrate being the dominant loss process [1]. We demonstrate the suppression of radiation loss by creating resonators on substrates with a phononic bandgap. We characterize the mechanical properties of these resonators for various substrate parameters and discuss prospects for the observation of quantum optomechanical effects at room temperature.\\[4pt] [1] S. Chakram \em et al.\em\ PRL 112, 127201 (2014) [Preview Abstract] 

Q1.00063: Experimental progress towards a Rydberg atomphotonsuperconductor quantum interface J.A. Isaacs, J.D. Pritchard, T. Xia, M.A. Beck, R. McDermott, M. Saffman Hybrid quantum computation exploits the individual strengths of various quantum technologies, enabling realization of a scalable quantum device capable of both fast gates and long coherence times. Our method combines the long coherence times of neutral atoms with the fast gates of superconducting qubits. We discuss experimental progress towards single atom trapping close to a superconducting resonator, including optimization of the resonator to maximize the quality factor and coupling strength for preliminary experiments performed at 4K. We use a new resonator design, incorporating 3D micro fabricated structures, that allows for strong electric field coupling to an atom trapped $\sim50~\mu$m above the resonator. Our scheme uses a novel twophoton Rydberg excitation via the $6S_{1/2}\rightarrow5D_{5/2}$ quadrupole transition to enable direct excitation of $nP_{3/2}$ states for strong electricdipole coupling to the cavity. This significantly reduces the Doppler mismatch compared to previous twophoton excitation schemes to enable high fidelity operations. First spectroscopy and Rabi oscillation results will be shown. [Preview Abstract] 

Q1.00064: Cold atoms coupled with mechanical oscillators Jose Valencia, Cris Montoya, Gambhir Ranjit, Andrew Geraci, Matt Eardley, John Kitching Mechanical resonators can be used to probe and manipulate atomic spins with nanometer spatial resolution and singlespin sensitivity, ultimately enabling new approaches in neutralatom quantum computation, quantum simulation, or precision sensing. We describe our experiment that manipulates the spin of trapped, cold Rb atoms using magnetic material on a cantilever. Cold atoms can also be used as a coolant for mechanical resonators: we estimate that~ground state cooling of an optically trapped nanosphere is achievable when starting at room temperature, by sympathetic cooling of a cold atomic gas optically coupled to the nanoparticle. [Preview Abstract] 

Q1.00065: Towards Radiation Pressure Measurement Using the Microresonator Test Mass Robinjeet Singh, Jonathan Cripe, Adam Libson, Garrett Cole, Nergis Mavalvala, Thomas Corbitt We observe the radiation pressure effects of light on the micromechanical resonator. Such measurements serve as initial steps towards testing macroscopic quantum mechanics and hence developing Quantum Non Demolition techniques for future Laser Interferometer Gravitational Observatory. [Preview Abstract] 

Q1.00066: Atom Entanglement in Nanophotonic Cavity QED Polnop Samutpraphoot, Thibault Peyronel, Crystal Senko, Manuel Endres, Alexander Keesling, Jeff Thompson, Tobias Tiecke, Kali Nayak, Vladan Vuletic, Mikhail Lukin Photons in a nanoscale photonic crystal waveguide cavity can be strongly coupled to individual trapped atoms due to the tight confinement of the optical mode. This platform enables a novel realization of an efficient atomphoton quantum interface for quantum networks [1]. We present experimental progress towards entanglement of two trapped atoms mediated by cavity photons. This approach can be used for realizing efficient quantum gates [2] with applications to integrated quantum networks and studies of manybody physics with lightmediated interactions. \\[4pt] [1] T. G. Tiecke, J. D. Thompson, N. P. de Leon, L. R. Liu, V. Vuletic and M. D. Lukin, Nature 508, 241 (2014)\\[0pt] [2] J. Borregaard, P. K\'om\'or, E. M. Kessler, A. S. S{\o}rensen, M. D. Lukin, arXiv:1501.00956 [Preview Abstract] 

Q1.00067: Probing Planckscale physics with optomechanical systems Igor Pikovski, Michael Vanner, Markus Aspelmeyer, Myungshik Kim, Caslav Brukner The ability to manipulate and to control quantum systems in novel regimes provides new ways to test our current understanding of physics. Here we show that some phenomenological models of quantum gravity can be probed with pulsed optomechanical systems. We introduce a scheme in which possible modifications of the canonical commutation relation of the center of mass mode of a massive mechanical oscillator can be tested. Our protocol utilizes quantum optical control and readout of the mechanical system and can probe possible deviations from the quantum commutation relation even at the Planck scale. We show that the scheme is within reach of current technology and thus opens a feasible route for tabletop experiments to test possible quantum gravitational phenomena. [Preview Abstract] 

Q1.00068: QUANTUM MEASUREMENT 

Q1.00069: Trapped ion system for for multispecies quantum control David Hanneke Many atoms and molecules possess interesting spectroscopic transitions, but lack dissipative transitions useful for control and detection of internal states. In particular, molecules are useful candidates for quantum memories, lowtemperature chemistry studies, tests of fundamental symmetries, and searches for timevariation of fundamental constants, but most lack a convenient cycling transition. By cotrapping a molecular ion with an atomic ion, the atom can provide all dissipation and detection. We present a system capable of such quantum control and report progress towards its use. [Preview Abstract] 

Q1.00070: Correlationenhanced Metrology with Mechanical Parametric Amplifiers Hil Fung Harry Cheung, Laura Chang, Yogesh Sharad Patil, Srivatsan Chakram, Mukund Vengalattore Quantum correlations between the two arms of a mechanical parametric amplifier [1, 2] can be used to realize sensing beyond the standard quantum limit. We use nondegenerate mechanical parametric oscillators made of silicon nitride membrane resonators to demonstrate mechanical amplitude squeezing. This is the acoustic equivalent of intensity difference squeezing observed in optical parametric oscillators. We use the strong correlations between the nondegenerate modes to realize subthermal force sensitivities through noise cancellation and signal enhancement schemes. Our classical realization of enhanced metrology in a platform amenable to quantum optomechanics and nonclassical state preparation paves the way for quantum nonlinear sensing.\\[4pt] [1] Y. S. Patil \em et al.\em\ arXiv:1410.7109\newline [2] S. Chakram \em et al.\em\ arXiv:1412.8536 [Preview Abstract] 

Q1.00071: Spatial Structure of Quantum Noise in a Squeezed Vacuum Field Mi Zhang, R. Nicholas Lanning, Zhihao Xiao, Jonathan P. Dowling, Irina Novikova, Eugeniy E. Mikhailov We used interaction of laser light with a dense vapor of Rb atoms to modify quantum statistics of the optical field and generated a squeezed vacuum state of light with 2dB reduction in the measured quantum noise compared to the standard quantum limit. We observe that the detected quantum noise suppression strongly depends on the shape of a spatial mask inserted into the optical beam after its propagation through atomic Rb vapor. Our study of the resulting spatial distribution of the quantum noise shows that the squeezed field was generated in a spatial mode different from the mode of the pump field. Moreover, the squeezed field consisted of several spatial modes with various squeezing parameters. Our theoretical model suggests that the squeezing field can be decomposed in a small subset of LaguerreGaussian modes. It is possible to enhance the signal to noise ratio of optoatomic sensors if the precise shape of the squeezed light mode is known. Thus our research has potential impact on precision metrology, quantum memory, and communication applications. [Preview Abstract] 

Q1.00072: Techniques for studying magnetic materials with NVdiamond Huiliang Zhang, Francesco Casola, Toeno Van der sar, Mehmet Onbasli, Caroline Ross, Amir Yacoby, Ronald Walsworth The study of real space condensed matter magnetism with high spatial resolution is an active research field of central importance in fundamental experimental solid state physics, spintronics and with potential applications in information processing. We present a set of novel experimental methods, based on nitrogenvacancy (NV) centers in diamonds, recently proposed by theory [1] and whose feasibility is currently being investigated in our lab. We discuss how these ideas are tightly linked with the remarkable possibility of creating a magnetic coherent coupling between distant NVs. We will also report our current efforts to integrate NVdiamond fabrication with Yttrium Iron Garnet (YIG), which will serve as a test bed for these measurements. \\[4pt] [1] P. Stano et al., PRB 88, 045441 (2013); L. Trifunovic et al., arXiv:1409.1497 (2014); L. Trifunovic et al., PRX 3, 041023 (2013). [Preview Abstract] 

Q1.00073: New Frontiers in Spin Squeezing Kevin Cox, Joshua Weiner, Graham Greve, James Thompson Entangled states of atoms are becoming increasingly practical as a resource for enhancing precision measurements. In a recent experiment, we generated and directly observed 10.2(6) dB of spin squeezing using a quantum nondemolition (QND) measurement, one of the largest amounts of directly observed spin squeezing in an atomic ensemble to date. In this poster, we present progress and recent results from a nextgeneration spin squeezing experiment aimed at generating even larger amounts of entanglement in an ensemble of Rb atoms. [Preview Abstract] 

Q1.00074: Low Temperature Chemistry with Trapped Ions Joan Marler At temperatures 5 orders of magnitude less than room temperature individual ions and ensembles of ions can be studied and manipulated with an unprecedented level of control. To achieve these temperatures ions are isolated in an rftrap and lasercooled to temperatures in which their internal states can be measured, set and switched at the individual ion level. Since the earliest days of ion trapping, scientists have appropriated these traps to perform experiments in fields as diverse as fundamental particle physics, antimatter science, quantum information science, condensed matter, and chemistry. At Clemson near term experiments include following state to state chemical reactions, studying chemistry relevant to astrophysical systems and performing highly accurate measurements of carbon containing organic systems. Additional experiments will explore beyond the standard model physics using Highly Charged Ions (HCIs) from the Clemson EBIT which have been subsequently trapped in an ion trap. [Preview Abstract] 

Q1.00075: QUANTUM COMPUTATION AND SIMULATION 

Q1.00076: Quantum Simulation of Quantum Field Theory with a Trapped Ion System Xiang Zhang, Kuan Zhang, Yangchao Shen, Jingning Zhang, ManHong Yung, Kihwan Kim, Julen Simon, Lucas Lamata, Enrique Solano, Jorge Casanova We report on the experimental quantum simulation of interacting bosonic and fermionic quantum field modes with a trapped ion system [1]. We consider a basic model of only one fermion and one antifermion interacting through a bosonic field mode, which reveals interesting features such as selfinteractions, particle creation and annihilation and nonperturbative regimes. We experimentally study these phenomena by manipulating the internal degrees of freedom of a multilevel single $^{171}\mathrm{Yb}^+$ ion and its motional state, based on the proposal of Ref. [1]. Our experimental scheme is a scalable approach and can be extended beyond the limit of classical computation of quantum field theory when more fermions and bosons are included. \\[4pt] [1] J. Casanova, et al., Phys. Rev. Lett, 107, 260501 (2011) [Preview Abstract] 

Q1.00077: Realization of arithmetic addition and subtraction in a quantum system Mark Um, Junhua Zhang, Dingshun Lv, Yao Lu, Shuoming An, JingNing Zhang, Kihwan Kim, M.S. Kim, Hyunchul Nha We report an experimental realization of the conventional arithmetic on a bosonic system, in particular, phonons of a 171Yb+ ion trapped in a harmonic potential. The conventional addition and subtraction are totally different from the quantum operations of creation $\hat{a}^{\dagger}$ and annihilation $\hat{a}$ that have the modification of $\sqrt{n}$ factor due to the symmetric nature of bosons. In our realization, the addition and subtraction do not depend on the number of particles originally in the system and nearly deterministically bring a classical state into a nonclassical state. We implement such operations by applying the scheme of transitionless shortcuts to adiabaticity [1,2] on antiJaynesCummings transition. This technology enables quantum state engineering and can be applied to many other experimental platforms.\\[4pt] [1] M. V. Berry, J. Phys. A 42, 365303 (2009).\\[0pt] [2] J. Zhang, et al., Phys. Rev. A 89, 013608 (2014). [Preview Abstract] 

Q1.00078: Adiabatic Quantum Search in Open Systems Dominik Wild, Sarang Gopalakrishnan, Michael Knap, Norman Yao, Mikhail Lukin We explore the dynamics of an adiabatic quantum search algorithm in an open system in order to identify potential speedup or slowdown due to the coupling to the environment. We show that even for a very general environment, Grover's scaling of the computation time with the size of the search space remains optimal. In the presence of a bosonic environment, we observe a dynamic phase transition from underdamped to overdamped evolution of the system as a function of the noise spectral density. The phase transition is further reflected by a change of the thermalization rate. For underdamped evolution, the thermalization rate obeys the optimal, quantumenhanced scaling with the size of the search space, whereas the scaling is classical in the overdamped regime. We provide a physical interpretation of the phase transition in terms of a renormalized tunneling rate and hence show that quantum speedup is only attainable in the underdamped phase. [Preview Abstract] 

Q1.00079: Characterization of single and twoqubit gates in a 2D neutral atom qubit array Tian Xia, Kara Maller, Martin Lichtman, Michal Piotrowicz, Alex Carr, Larry Isenhower, Mark Saffman We have developed a 2D array of optically trapped single atom qubits for quantum computation experiments. We characterize single qubit Clifford gate operations with randomized benchmarking achieving global and site selected gates with fidelities close to fault tolerance thresholds for quantum computation. An average fidelity of 0.9983, limited by the qubit T2 coherence time, is measured for global microwave driven gates applied to a 49 qubit array. Single site gates are implemented with a focused laser beam to Stark shift the microwaves into resonance at a selected site. At Stark selected single sites we observe fidelities of 0.9923 and an average spin flip crosstalk error at other sites of 0.002. A twoqubit Rydberg blockade interaction provides a CNOT gate which is used to create entangled Bell pairs. The fidelity is characterized with parity oscillation measurements. The influence of twophoton Stark shifts on the gate matrix and fidelity is studied. We show how to select excitation parameters to suppress the groundRydberg differential Stark shift. [Preview Abstract] 

Q1.00080: Efficient and stringent certification of boson sampling in symmetric waveguide lattices Robert Keil, Christoph Dittel, Thomas Kauten, Gregor Weihs, Armando PerezLeija, Steffen Weimann, Maxime Lebugle, Alexander Szameit, Malte Tichy Nonuniversal quantum computers dedicated to specific tasks, such as bosonsampling, are envisioned to outperform the classically computable limit much sooner than universal quantum computers. However, once this regime is reached, the very hardness of boson sampling excludes any straightforward efficient verification of the results. A computationally accessible while physically nontrivial instance of the problem based on Fourier matrices was recently proposed to prove manyparticle interference and thereby benchmark the functionality of a candidate device. Yet, this is singular case remains challenging to implement experimentally. Here, we greatly generalize this approach by formulating a certification criterion based uniquely on mirror symmetry of the network, leaving the exact form of the scattering matrix open. For mirror symmetric inputs, the symmetry of the system enforces the suppression of around $50\% $ of a priori possible output states. Since this suppression relies on genuine multiparticle interference, it represents a stringent certification criterion that can be used to ensure the functionality of bosonsamplers. This certification method is efficient and scalable to very large particle numbers and system sizes. As an optical network adhering to this symmetry, we propose to implement a $J_{x} $ photonic lattice, as introduced in Phys. Rev. A 87, 022303, with an engineered coupling distribution. [Preview Abstract] 

Q1.00081: A Cryogenic Linear Paul Trap for Quantum Simulation Paul Hess, Harvey Kaplan, Aaron Lee, Brian Neyenhuis, Lexi Parsagian, Phil Richerme, Jake Smith, Christopher Monroe Ions confined in radio frequency Paul traps are a useful tool for quantum simulation of longrange spinspin interaction models. As the system size increases, classical simulations cannot fully compute the properties of the exponentially growing Hilbert space, necessitating quantum simulation for accurate predictions. Current experiments are limited to less than 20 qubits due to the fragile nature of linear ion chains. Even at UHV pressures, collisions with background gas particles are sufficient to melt the ion crystal and frequent enough to disrupt the accumulation of statistics. We present progress towards the construction of a cryogenic ion trap apparatus, designed to cryopump background gas within the 4K chamber. The resulting reduction in pressure will allow robust trapping of up to 100 ions in a single chain. Cooling is provided by a closed cycle cryostat with a gas mediated thermal linkage which mechanically decouples the ion trap from the vibrating cold head. A spherical octagon surrounding the ion trap allows optical access for global and individual addressing beams and high numerical aperture fluorescence collection. [Preview Abstract] 

Q1.00082: Reversing Molecular Ion Formation for Quantum Simulations in a Coulomb Crystal of Be$^+$ Ions Brian Sawyer, Justin Bohnet, Joseph Britton, John Bollinger For more than a decade, the internal states of cold, trapped atomic ions have been used as qubits for quantum logic operations. Penning traps allow for confinement and manipulation of very large ion crystals ($>>$ 100) in 1D, 2D, or 3D configurations. Quantum simulation experiments with 2D crystals in Penning traps rely on engineered couplings between Be$^+$ internal spin and collective ion motion perpendicular to the crystal plane. Highfidelity quantum logic operations require precise knowledge of the crystal mode structure, but mode eigenfrequencies and eigenvectors can shift over time as impurity hydride ions (i.e. BeH$^+$) are formed in the crystal via chemistry with background H$_2$ molecules in the vacuum chamber. To mitigate this, we have demonstrated [1] a singlephoton photodissociation scheme for BeH$^+$ that efficiently recovers Be$^+$ ions within the crystal. A commercial excimer laser operating at 157 nm provides the photodissociation light, and we note that a 193 nm excimer should efficiently recover Mg$^+$ and Al$^+$ from their respective hydride species, making this technique applicable to a wide range of ion species used in quantum information experiments.\\[4pt] [1] B.C. Sawyer et al., Phys. Rev. A 91, 011401(R) (2015). [Preview Abstract] 

Q1.00083: Measuring nonequilibrium spectral functions in a iontrapbased quantum spin simulator Bryce Yoshimura, James Freericks Ref.\footnote{ M. Knap, A. Kantian, T. Giamarchi, I. Bloch, M. Lukin, and E. Demler, Phys. Rev. Lett. \textbf{111}, 147205 (2013)} proposed to use a variant of Ramsey interferometry to measure the retarded spinspin correlation function as functions of space and time. This protocol can be carried out in a linear Paul trap quantum spin simulator if singlesite addressing of the spins is possible. A measure of the zcomponent of the spin translates into the twotime spinspin correlation function of the transverse field Ising model. Since the system starts of in the ground state for large transverse field, and as the field is ramped down, it creates nonequilibrium diabatic excitations, the retarded Green's function that results is a nonequilibrium, stateselective Green's function. In this work, we present calculations of the behavior of these manybody correlation functions both as functions of time and of frequency. [Preview Abstract] 

Q1.00084: Experimental measurement of ntime correlation functions in a trapped ion Shuaining Zhang, Yangchao Shen, JinNing Zhang, ManHong Yung, J.S. Pedernales, Lucas Lamata, J. Casanova, Enrique Solano, Kihwan Kim We implement an algorithm to measure ntime correlation functions of the motional degree of freedom of a trapped 171Yb+ ion by following the proposal in Ref. [1]. The algorithm requires a system undergoing a time evolution and an ancillary qubit on which we perform conditional gates. We measure bosonic field correlations such as $g^{(1)}$ and $g^{(2)}$ functions. For the case of an electromagnetic field, $g^{(1)}$ and $g^{(2)}$ are well known in quantum optics as electric field and intensity correlation functions, respectively. This scheme can be extended to a system including also spins and used to characterize relevant physical magnitudes, such as linear response functions. \\[4pt] [1] J. S. Pedernales, et al., Phys. Rev. Lett. 113, 020505 (2014). [Preview Abstract] 

Q1.00085: Exciton Resonances in Novel Silicon Carbide Polymers Larry Burggraf, Xiaofeng Duan A revolutionary technology transformation from electronics to excitionics for faster signal processing and computing will be advantaged by coherent exciton transfer at room temperature. The key feature required of exciton components for this technology is efficient and coherent transfer of longlived excitons. We report theoretical investigations of optical properties of SiC materials having potential for hightemperature excitonics. Using CarParinello simulated annealing and DFT we identified lowenergy SiC molecular structures. The closoSi$_{12}$C$_{12}$ isomer, the most stable 1212 isomer below 1100 C, has potential to make selfassembled chains and 2D nanostructures to construct exciton components. Using TDDFT, we calculated the optical properties of the isomer as well as oligomers and 2D crystal formed from the isomer as the monomer unit. This molecule has large optical oscillator strength in the visible. Its highenergy and lowenergy transitions (1.15 eV and 2.56 eV) are nearly pure oneelectron silicontocarbon transitions, while an intermediate energy transition (1.28 eV) is a nearly pure carbontosilicon oneelectron charge transfer. These results are useful to describe resonant, coherent transfer of dark excitons in the nanostructures. [Preview Abstract] 

Q1.00086: STOPPING AND SLOWING LIGHT 

Q1.00087: Photon number dependent group velocity in vacuum induced transparency Nikolai Lauk, Michael Fleischhauer Vacuum induced transparency (VIT) is an effect which occurs in an ensemble of three level atoms in a $\Lambda$ configuration that interact with two quantized fields. Coupling of one transition to a cavity mode induces transparency for the second field on the otherwise opaque transition similar to the well known EIT effect. In the strong coupling regime even an empty cavity leads to transparency, in contrast to EIT where the presence of a strong control field is required. This transparency is accompanied by a reduction of the group velocity for the propagating field. However, unlike in EIT the group velocity in VIT depends on the number of incoming photons, i.e. different photon number components propagate with different velocities. Here we investigate the possibility of using this effect to spatially separate different photon number components of an initially coherent pulse. We present the results of our calculations and discuss a possible experimental realization. [Preview Abstract] 

Q1.00088: A LatticeTrapped and CavityEnhanced HighQuality Quantum Memory ShengJun Yang, XuJie Wang, XiaoHui Bao, JianWei Pan Quantum memory plays an increasing essential part in many applications of quantum information science. Currently, the intense research and crucial challenge is that integration of a full functional quantum memory with various highperformance properties in a single system. Storage lifetime and retrieval efficiency are the two most important qualities of quantum memory, especially indispensable for quantum repeater and longdistance quantum communication. Here based on techniques of magic optical lattice trap and ring cavity enhancement, we experimentally achieved a highquality cold atom quantum memory. The initial intrinsic retrieval efficiency is up to 77(5)\%, with an $\rm{e^{1}}$storage lifetime about 0.25 sec for the first time. Such high effective and longlived quantum memory should be significantly important for quantum communication and cryptography, and would truly stimulate a first practical demonstration of long distance quantum repeaters in the near future. [Preview Abstract] 

Q1.00089: FourWave Mixing reduction for EITbased stored light Gleb Romanov, Irina Novikova We study Electromagnetically Induced Transparency (EIT) based quantum memory. EIT conditions introduce FourWave Mixing (FWM) that leads to signal gain and generation of the additional Stokes field, causing additional noise in quantum memory experiments. We investigate the possibility of reducing the FWM and the associated gain by introducing absorption for the Stokes field. Here we propose to use a natural abundance cell with a buffer gas, with storage realized on one of the isotopes. The second isotope can be used to create a Raman absorption resonance for the Stokes field using a strong offresonant field. Absorption of the Stokes photons should lead to reduced gain and the associated noise for the probe. I will report on our progress with this experiment. [Preview Abstract] 

Q1.00090: MATTER WAVE INTERFEROMETRY 

Q1.00091: Dual interferometry with a tunable point of minimum magnetic sensitivity Eduardo Gomez Garcia, Saeed Hamzeloui, Daniel MartinezArias, V\'Ictor Manuel Valenzuela The clock transition is well known for its minimum magnetic sensitivity at B$=$0. The hyperfine transition between F$=$1, m$=$1 and F$=$2, m$=$1 in 87Rb also shows a point of minimum magnetic sensitivity but it happens at a field of 3.2 Gauss. An interferometer that uses a mixture of the previous two transitions gives a minimum of magnetic sensitivity at a tunable value of the magnetic field between 0 and 3.2 Gauss. The desired magnetic field value can be selected by varying the population in each transition. The relative populations are controlled with a microwave pulse joining states in both interferometers. We implement the mixture interferometer using single photon transitions only, taking advantage of an arbitrary wave synthesizer. [Preview Abstract] 

Q1.00092: Waveguide BEC Interferometry with Painted Potentials Malcolm Boshier, Vyacheslav Lebedev, Carlo Samson, Changhyun Ryu Waveguide atom interferometers\footnote{ Y. Shin et al., Phys. Rev. Lett. \textbf{92}, 050405 (2004). T. Schumm et al., Nat Phys \textbf{1}, 57 (2005).} offer the possibility of long measurement times in a compact geometry, which can be an advantage over free space interferometers if the dephasing due to interatomic interactions can be controlled. We are investigating waveguide BEC interferometers created with the painted potential,\footnote{K. Henderson et al., New J. Phys. \textbf{11}, 043030 (2009).} a technique which allows for the creation and manipulation of BECs in arbitrary 2D potentials. The goal is to measure a linear acceleration of the device. The painted potential allows new approaches to the initial splitting of the BEC. For example, instead of smoothly deforming a single well potential into a double well, it is possible instead to gradually remove a weak link\footnote{C. Ryu et al., Phys. Rev. Lett. \textbf{111}, 205301 (2013).} coupling two initially separated waveguides. This strategy should reduce excitations created in the splitting process. We are currently implementing such schemes and measuring the coherence time of the BEC after division. We will present the results of these measurements, and report progress towards measuring linear accelerations. [Preview Abstract] 

Q1.00093: Cold Strontium Ion Source for Ion Interferometry Jarom Jackson, Dallin Durfee We are working on a cold source of Sr Ions to be used in an ion interferometer. The beam will be generated from a magnetooptical trap (MOT) of Sr atoms by optically ionizing atoms leaking out a carefully prepared hole in the MOT. A single laser cooling on the resonant transition (461nm) in Sr should be sufficient for trapping, as we've calculated that losses to the atom beam will outweigh losses to dark states. Another laser (405nm), together with light from the trapping laser, will drive a two photon transition in the atom beam to an autoionizing state. [Preview Abstract] 

Q1.00094: Optimization of the Geometric Phase Sensitivity of an Array of Atom Ring Interferometers Karina SandovalSanchez, Christian Campo, Tabitha Rivera, John Toland Sagnac, and AharonovBohm phase shifts are important geometric phase shifts in atom interferometry. These phase shifts characterize rotational and magnetic field interference effects respectively. Theoretical explorations have shown that a series of ring interferometers can be connected in series to increase the sensitivity of the overall device while keeping the maximum path separation less than the coherence length of the atoms. It has also been shown that the application of an area chirp to the rings will further enhance the sensitivity of the array of rings to geometric phase shifts. Area chirp refers to characterizing all of the rings in the array to a fixed percentage of a reference ring, this allows for the phase shifts in each ring to be characterized by one ring. The goal of this project is to determine a set of parameters namely kL, the product of the ring circumference and the wave number and $\gamma $, the chirp factor for the area chirp, that optimize the geometric phase sensitivity for an array of N rings. We model the transmission coefficient of a quantum matter wave through an area chirped array of interferometers as a function of phase, using transfer matrices to represent the transmission and reflection of individual rings in the array. Isolated transmission resonances represent the domain of interest, these are regions of high phase sensitivity. After optimizing a ring array without loss we apply velocity broadening to the input matter waves to investigate a more realistic output. [Preview Abstract] 

Q1.00095: SCIENCE WITH XUV AND XRAY FREEELECTRON LASERS 

Q1.00096: Complex Resonancemediated Ionization Dynamics Driven by Intense Femtosecond XFEL Pulses in Xenon and Krypton Atoms Phay Ho, Elliot Kanter, Linda Young We present the calculated multiphoton ionization dynamics of Xe and Kr atoms initiated by SASE XFEL pulses and predict the behavior of these atoms in the newly available seeded XFEL pulses with narrow bandwidth for a range of photon fluences and xray photon energies. Understanding of the ionization dynamics is central to realize potential applications of these pulses. The method is based on our recently developed MonteCarlo rate equation (MCRE) approach [1], which for the first time successfully demonstrates the role of ``hidden resonances'' [2] and captures the responsible resonanceenhanced xray multiple ionization (REXMI) pathways that lead to unexpectedly high charge states in Ar, Kr and Xe. The MCRE approach efficiently accounts for photoionization, Auger decay and fluorescence processes and boundtobound transitions. We found that the intricate landscape of resonances hidden in various charge states leads to unusual pulse parameter dependences in ion yields revealed in both Xe and Kr atoms. The importance of these individual resonances is selectively magnified or suppressed by the pulse fluence, in addition to the atomic excitation energies covered by the XFEL photon energy and bandwidth.\\[4pt] [1] P. J. Ho~\textit{et al}. Phys. Rev. Lett~\textbf{113}, 253001 (2014).\\[0pt] [2] E. P. Kanter~\textit{et al}. Phys. Rev. Lett~\textbf{107}, 233001 (2012). [Preview Abstract] 

Q1.00097: FewXUVphoton laserassisted double ionization of helium Aihua Lui, Uwe Thumm We studied the fewphoton IR laserassisted double ionization of helium in ultrashort XUV pulse(s) by numerically solving the timedependent Schr{\"o}dinger equation in full dimensionality within a finiteelement discretevariablerepresentation scheme [1]. We calculated energy and joint angle distributions in coplanar geometry, where the emitted electron momenta and identical polarization axis of the linearly polarized XUV and IR pulses lie in a plane. By analyzing joint angle distributions and asymmetries for twoXUVphoton double ionization, we identify ``sequential'' and ``nonsequential'' contributions for ultrashort XUV pulses whose spectra overlap the sequential ($\hbar\omega>$ 54.4 eV) and nonsequential (39.5 eV $<\hbar\omega<$ 54.4 eV) double ionization regimes. In addition, we show that emission angles between the two photoelectrons can be controlled by adjusting parameters of the XUV and assisting IR pulse. \\[4pt] [1] A. Liu and U. Thumm, Phys. Rev. A \textbf{89}, 063423 (2014). [Preview Abstract] 

Q1.00098: The LAMP instrument at the LCLS Timur Osipov, JeanCharles Castagna, Christoph Bostedt, Hui Xiong, Ken Ferguson, Maximilian Bucher, Nora Berrah We have commissioned and used a new instrument at the Linac Coherent Light (LCLS) Source at SLAC National Laboratory called LAMP. It consists of several detectors housed in a double chambered vacuum system. One detection scheme offered relies on the use of a double velocity map imaging (VMI) spectrometer which enables research in the gas phase such as molecular dynamics experiments. The latter are monitored via the detection of electron and ionic fragments resulting from xray photoabsorption of xray photons. With this new tool, we can record the different fragmentation pathways by measuring multiparticles ionion coincidences/multiparticle correlations. We can also simultaneously image the electrons momenta to capture the most detailed xray induced reaction in molecules and nanosystems. The other detection scheme offered consists of two imaging detectors of the pnCCD type for diffraction experiments of clusters and biospecimens. This instrument, available to any users, has the possibility to uncover new mechanisms in physics, chemistry and biology. [Preview Abstract] 

Q1.00099: Fragmentation Dynamics of Endohedral Fullerene Ho$_{3}$N@C$_{80}$ Ionized with Intense and Short XRay FEL Pulses Brendan Murphy, Hui Xiong, Li Fang, Timur Osipov, Edwin Kukk, Vladmir Petrovic, Heng Li, Emily Sistrunk, Richard Squibb, Raimund Feifel, Kenneth Ferguson, Jacek Krzywinski, Sebastian Sebastian, Markus Guehr, Christoph Bostedt, Philip Bucksbaum, Nora Berrah The photoionization and fragmentation dynamics of gas phase endohedral fullerenes Ho$_{3}$N@C$_{80}$ with intense femtosecond Xray pulses from the Linac Coherent Light Source (LCLS) free electron laser (FEL) have been investigated. The central photon energy of the xray pulses was set at 1530 eV, targeting the absorption of the 3d electron on Ho. Multiphoton ionization led to the highest charge state observed on the parent molecule to be Ho$_{3}$N@C$_{80}^{5+}$, suggesting a stable structure even with 5 charges on the parent molecule. We will present the different atomic and molecular fragments dynamics observed. [Preview Abstract] 

Q1.00100: Interference effects in one and twophoton ionization by femtosecond VUV pulses Elena V. Gryzlova, Ekaterina I. Staroselskaya, Alexei N. GrumGrzhimailo, Joel Venzke, Klaus Bartschat Investigations of coherent control of atomic and molecular processes have rapidly developed since the advent of coherent light sources such as Xray free electron lasers (XFELs) and achievements in high harmonic generation. In practice, radiation from XFELs contains a small fraction of the second harmonic, which is difficult to filter out but can strongly influence experimental data on the twophoton ionization process, such as the angular distribution. Specifically, the direct firstorder secondharmonic ionization process may interfere with, and possibly even dominate a secondorder twophoton process caused by the fundamental. While this interference has been investigated in the optical regime with manycycle pulses, possible effects due to short pulses, as well as a physical intermediate resonance state that may serve as a stepping stone for the secondorder process, need a careful study for particular experimental conditions. Here we consider the photo\ionization of atomic hydrogen for photon energies near the excitation energy of the 2p state (0.375~a.u.\ or 121.6 nm). We compare results obtained from a direct numerical solution of the timedependent Schr\"odinger equation and secondorder perturbation theory. [Preview Abstract] 

Q1.00101: TIMERESOLVED ELECTRON DYNAMICS AND ATTOSECOND SPECTROSCOPY 

Q1.00102: Attosecond timeresolved streaked photoemission from Mgcovered W(110) surfaces Qing Liao, Uwe Thumm We formulate a quantummechanical model [1,2] for infraredstreaked photoelectron emission by an ultrashort extreme ultraviolet pulse from adsorbatecovered metal surfaces. Applying this numerical model to ultrathin Mg adsorbates on W(110) substrates, we analyze streaked photoelectron spectra and attosecond streaking time delays [3] for photoemission from the Mg/W(110) conduction band and Mg(2p) and W(4f) core levels. Based on this analysis, we propose the use of attosecond streaking spectroscopy on adsorbatecovered surfaces with variable adsorbate thickness as a method for investigating (a) electron transport in condensedmatter systems and (b) metaladsorbateinterface properties at subatomic length and time scales. Our calculated streaked photoemission spectra and time delays agree with recently obtained experimental data.\\[4pt] [1] Q. Liao and U. Thumm, Phys. Rev. Lett. 112, 023602 (2014).\\[0pt] [2] Q. Liao and U. Thumm, Phys. Rev. A 89, 033849 (2014).\\[0pt] [3] U. Thumm, Q, Liao, E. M. Bothschafter, F. S\"u{\ss}mann, M. F. Kling, and R. Kienberger, in: Handbook of Photonics 1: ``Attosecond physics,'' ed. D. L. Andrew, ISBN:9781118225530, Chapter XIII: ``Attosecond streaking spectroscopy of atoms and solids'' (Wiley, January 2015). [Preview Abstract] 

Q1.00103: Attosecond plasmonic streaking from gold nanospheres Jianxiong Li, Uwe Thumm To study timeresolved photoemission from gold nanospheres, we developed a semianalytical quantummechanical approach. We use Mie theory to analytically calculate plasmonically enhanced fields near 10 to 200 nm gold nanospheres, driven by intense incident nearinfrared (NIR) or visible light pulses. We model the gold conduction band in based on spherical square well potentials. Our first numerical results for streaked photoelectron spectra from gold nanospheres show a 3 times increased streaking spectrum amplitude for incident 800 nm streaking pulses and 10 nm diameter gold nanospheres, as compared with calculations in which the plasmonic nearfield enhancement is switched off. [Preview Abstract] 

Q1.00104: Interpreting Attoclock Measurements of Tunnelling Times Olga Smirnova, Lisa Torlina, Felipe Morales, Jivesh Kaushal, Igor Ivanov, Anatoli Kheifets, Alejandro Zielinski, Armin Scrinzi, Harm Geert Muller, Misha Ivanov Recent experiments based on the attoclock setup opened the opportunity to timeresolve ionization dynamics in strong IR laser fields. However, reconstruction of ionization times from experiment poses theoretical challenges. We have used the combination of abinitio calculations with analytical RMatrix theory to resolve these challenges, without adhoc assumptions about the ionization process. Ionization in IR fields can be described as electron tunnelling under the barrier created by the field and the core potential. Thus, attoclock setup addresses the long standing question of tunnelling times: does an electron take a finite real time to pass under a barrier? For the hydrogen atom, our results show that optical tunnelling is instantaneous. Rather than real time delays, we show that it is the longrange Coulomb interaction with the core that is responsible for the angular shifts we see in the photoelectron spectra. We also consider multielectron systems and show how our method can be used to extract strongfield ionization delays associated with multielectron dynamics. [Preview Abstract] 

Q1.00105: High harmonic spectroscopy of hole dynamics: where is the hole created after tunnel ionization of a molecule? Olga Smirnova, Alex Harvey, Felipe Morales, Maria Richter, Misha Ivanov, Serguei Patchkovskii, Yann Mairesse Ultrafast ionization of a molecule creates a multielectron wavepacket in the ion. Its dynamics can be viewed as a motion of a hole. One of the most interesting questions, and one of the key experimental challenges, is to identify the initial shape, location and momentum of the created hole. If the hole is created via tunnel ionization, should it always be aligned with the direction of the laser electric field? Should it be initially located on the `downstream side' of the molecule, adjacent to the potential barrier through which the electron was removed by tunneling? We use high harmonic spectroscopy to address this question, combining accurate theoretical modelling with detailed experimental measurements. We find that the location of the hole does not follow the simplistic picture of adiabatic tunneling: the hole is not created adjacent to the potential barrier through which the electron tunnels out. Our results are obtained in the regime where several electronic states of the cation are strongly coupled by both the ionizing field and via the electronelectron correlation. The displacement of the hole might be indicative of correlationinduced timedelays during multiphoton ionization, similar to correlationinduced delays known for onephoton ionization. [Preview Abstract] 

Q1.00106: PulseShape Effects in Ionization of Atomic Hydrogen by ShortPulse XUV Intense Laser Radiation Klaus Bartschat, Joel Venzke, Alexei N. Grum Grzhimailo In a recent publication~[1], we investigated a displacement effect in strongfield atomic ionization by an XUV pulse. We found that the angular momentum of the ejected electron and, therefore, its angular distribution were strongly affected by the details in the short rampon/off characteristics of various pulses, all of which were otherwise identical with a plateau in the envelope function that was significantly longer than the rampon/off phase. In the present work, we studied the effect in more detail, especially regarding the role of the plateau, which is unlikely to occur in a realistic experimental setup. As expected~[2], great care must be taken in setting up theoretical models to ensure that the pulses are, at least in principle, experimentally realizable.\\[4pt] [1] I.A.~Ivanov, A.S.~Kheifets, K.~Bartschat, J.~Emmons, S.M.~Buczek, E.V.~Gryzlova, and A.N.~GrumGrzhimailo, Phys. Rev. A {\bf 90} (2014) 043401.\\[0pt] [2] L.B. Madsen, Phys. Rev. A {\bf 65} (2014) 053407. [Preview Abstract] 

Q1.00107: Pumpprobe Subadditivity in Photoelectron Emission from GaAs Evan Brunkow, Nathan Clayburn, Herman Batelaan, Timothy Gay Using an autocorrelator and a pulsed laser with an 800 nm center wavelength, 10 nJ/pulse, and pulse duration of $\sim$ 50 fs at the target, we have shown that photoemission from GaAs induced by coherent pump and probe pulses with a temporal separation from 0 to 100 fs has a relationship that is more than additive. This implies that either the emission process is slower than 100 fs or that another process is occurring that affects the emission process itself [1]. We also have data with delays of $\sim$ 0.5  16 ps between the pump and probe that shows a subadditive behavior, with a maximum effect of $\sim$ 11{\%} at 6 ps. We present several theories as to what is causing this effect. \\[4pt] [1] E. Brunkow \textit{et al.}, Bull. Am. Phys. Soc. \textbf{59} (2014) [Preview Abstract] 

Q1.00108: The effect of the attochirp on attosecond streaking Cory Goldsmith, Agnieszka JaronBecker, Andreas Becker Measurements invoking the use of attosecond pulses can be incorrectly interpreted if the chirp of such pulses is not taken into account. In this study, we use a physically intuitive analytical model to understand the effect a chirp in the extreme ultraviolet (XUV) attosecond pulse will have upon the delay observed in streaking experiments. It is known that both the photoionization crosssection of the system and the spectral and temporal characteristics of the attosecond pulse used will determine the relative timedependent probability of absorbing a particular photon energy. We additionally use an analytical method to calculate the streaking delay as a function of the absorbed photon energy and the time delay between the XUV and streaking pulses. Equipped with this information, we determine the expected value of the streaking delay observed when a chirped attosecond XUV pulse is used to initiate streaking experiments. We then demonstrate that depending on the chirp, the streaking delay can be changed by several attoseconds, which is on the order of the delays usually observed in such experiments. [Preview Abstract] 

Q1.00109: Nonlinear response of Indium Antimonide to femtosecond mid IR Evan Lang, Fedor Bergmann, Enam Chowdhury Indium Antimonide (InSb) is an important semiconductor in mid IR range whose nonlinear response to femtosecond pulses is not well characterized. Our goal is to measure the nonlinear response of nonthermally excited electrons of InSb using a pumpprobe experiment with 150fs pulses at nJ/pulse energy from a home built femtosecond fiber oscillator at 1550nm. The delay time between pump and probe was varied from 0 to 100ps with femtosecond resolution. The probe light was reflected from excited surface by the pump and its response captured with IR camera/photo detector. Details of the reflectivity dynamics will be discussed. [Preview Abstract] 

Q1.00110: Spectroscopic signatures of laserinduced nonadiabatic electron dynamics in H$_2^+$ Michelle Miller, Agnieszka JaronBecker, Andreas Becker In this theoretical investigation of molecular highorder harmonic generation, we identify a new mechanism resulting in a spectral minimum and nonodd harmonic generation when H$_2^+$ is driven at extended internuclear distances ($\approx$ 7.0 au) by a midinfrared laser source (1.4 $\mu$m  1.8 $\mu$m) of moderate intensity. Manifestation of this minimum is connected to the subhalffield cycle transient localization of the electron upon alternating nuclear centers. We establish the sensitivity of this feature to driving field parameters, eliminating or increasing the number of minima by reducing the driving wavelength or increasing the laser intensity, respectively. The robustness of the minimum feature to distributions of laser field intensities, internuclear distances and carrier envelope phase is also demonstrated. [Preview Abstract] 

Q1.00111: COLLISIONS INVOLVING ANTIMATTER, CLUSTERS AND SURFACES 

Q1.00112: An Investigation of PositroniumHydrogen Collision S.J. Ward, Denton Woods, P. Van Reeth Elastic positroniumhydrogen (PsH) scattering is of interest as it is a fundamental fourbody Coulomb process. Using the complex Kohn variational method, we compute the phase shifts for elastic PsH scattering for the six lowest partial waves [1,2]. The $^{1,3}S$ and $^{1,3}P$wave phase shifts can be viewed as benchmark results. Using a quantum defect theory [3], we determine $^{1,3}S$ and $^{1,3}P$ scattering lengths and $^{1,3}S$ effective ranges. We also compute elastic integrated, elastic differential and momentumtransfer cross sections.\\[4pt] [1] Denton Woods, S.~J.~Ward and P.~Van~Reeth, {\it unpublished} (2015).\\[0pt] [2] Denton Woods, P.~Van~Reeth and S.~J.~Ward, http://meetings.aps.org/link/BAPS.2014.DAMOP.Q1.55.\\[0pt] [3] Bo~Gao, Phys. Rev. A {\bf 58}, 4222 (1998). [Preview Abstract] 

Q1.00113: Positron cooling by vibrational and rotational excitation of molecular gases J.R. Danielson, M.R. Natisin, C.M. Surko Measurements of positron temperature as a function of time are presented\footnote{\small M. R. Natisin, J. R. Danielson, C. M. Surko, {\it J. Phys. B} {\bf 47}, 225209 (2014).} when a positron gas, confined in an electromagnetic trap at an elevated temperature ($\geq1200$~K), is cooled by interactions with the 300~K molecular gases CF$_4$, N$_2$ and CO. A simple model describing positron cooling and thermalization by coupling to vibrational modes (CF$_4$, CO), dipolecoupled rotational modes (CO), and quadrupolecoupled rotational modes (CO, N$_2$) is presented with coolingrate predictions calculated in the Born approximation. Comparisons to the measured positron coolingrate curves permit estimates of the magnitudes of the relevant cross sections. The results are compared with experiment for the case of vibrational excitation, where direct measurements exist; and they provide estimates of the rotational excitation cross sections where direct measurements are not currently possible. A new experiment using cryogenically cooled buffer gases is underway, and measurements of positron cooling to 50 K will be presented. [Preview Abstract] 

Q1.00114: Formation of BufferGasTrap Based Positron Beams M.R. Natisin, J.R. Danielson, C.M. Surko Presented here are experimental measurements, analytic expressions and simulation results for pulsed, magnetically guided positron beams formed using a PenningMalmberg style buffer gas trap.\footnote{\small M. R. Natisin, J. R. Danielson, C. M. Surko, {\it Phys. Plasma} submitted.} Analytic expressions are developed which describe the evolution of the beam energy distributions, both parallel and perpendicular to the magnetic field, as the beam propagates through regions of varying magnetic field. Simulations of the beam formation process are presented, with the parameters chosen to accurately replicate experimental conditions. The initial conditions and ejection parameters are varied systematically in both experiment and simulation, allowing the relevant processes involved during beam formation to be explored. A new experiment will also be discussed in which positrons are cooled to 50 K prior to beamformation, thus allowing the creation of a cryogenic positron beam with better energy resolution than previously available. [Preview Abstract] 

Q1.00115: Role of inelastic collisions in explanation of the effect of rotating wall trap of electrons/positrons in gases Zoran Petrovic, Srdjan Marjanovic The only existing explanation of the rotating wall positron trap operating in the low space charge limit (swarm) [ref] is based on momentum transfer collisions to represent the collisions of positrons in gas and to facilitate the effective narrowing of the profile and heating/cooling succession. The collisions are represented through a viscous term of a simple transport equation. In that model effective viscosity term is used to fit the observed data with no attention paid to the magnitude of the term compared to the measured or theoretically predicted values. We apply a well tested Monte Carlo technique whereby all interactions may be described by exact experimental or theoretical cross sections. We separate effects due to inelastic processes with small and large energy losses (i.e. on vibrational or rotational excitation versus electronic excitation). It turns out that large energy loss processes are essential in narrowing the profile but also that low energy loss processes define thermalization to the room temperature or lower and allow cooling of the ensemble. Heating was necessary to allow narrowing of the profile but the particles have to return to the thermal equilibrium with low fields. [Preview Abstract] 

Q1.00116: Transport of Positrons in Arbitrary Configurations of Electric and Magnetic Fields Zoran Petrovic, Sasa Dujko, Ana Bankovic, Srdjan Marjanovic, Ron White In realistic geometries in gas filled positron traps electric and magnetic fields may not be always along the same axis or perpendicular. It has been shown for electrons that for arbitrary angles a wide variety of effects may occur. Most importantly controlling the angle may control diffusion and thus affect strongly the losses. We have performed calculations of transport coefficients for molecular hydrogen and carbontetrafluoride. Monte Carlo technique was supplemented by novel development of solution of Boltzmann equation for arbitrary configuration of electric and magnetic fields. Both flux and bulk variants of transport coefficients were considered. It was found that it is possible to control diffusion and hence diffusion losses in a wide range of values by varying the angle of magnetic field. In addition it was found that the configuration will affect the mean energy and hence the losses due to Ps formation. The magnitude of effects depends strongly on shapes of the cross sections for positron scattering. [Preview Abstract] 

Q1.00117: ELECTRONATOM COLLISIONS 

Q1.00118: Electron Impact ionization of Neon atoms using screening potential approach Hari P. Saha We will report the results of triple differential cross section for electron impact ionization of raregas atom, neon using our extended MCHF method [1]. It is well known that electron correlation effects in both the initial and the final states are very important. To incorporate these effects we will use both HartreeFock and multiconfiguration HartreeFock methods to account for electron correlation in the initial state. The electron correlation in the final state will be taken into account using the angledependent screening potential approximation [2,3]. Our results will be compared with available experimental observations and accurate theoretical calculations.\\[4pt] [1] Hari P. Saha, J. Phys. B 47, 175005 (2014).\\[0pt] [2] M.R.H. Rudge, Rev. Mod. Phys. 40, 564 (1968).\\[0pt] [3] C.Pan and A.F Starace, Phys. Rev. Lett. 67, 185 (1991); Phys. Rev. A45, 4588 (1992). [Preview Abstract] 

Q1.00119: EkectronImpact Excitation of C$^+$ A.J. Pearce, C.P. Ballance, S.D. Loch, M.S. Pindzola Electronimpact excitation cross sections are calculated for ground and excited states of C$^+$ using the Rmatrix with pseudostates method. We used the configurations $1s^2 2s^2 nl (3s \leq nl \leq 12g)$, $1s^2 2s 2p nl (2p \leq nl \leq 12g)$, $1s^2 2p^2 nl (2p \leq nl \leq 12g)$, $1s^2 2s 3s^2$, and $1s^2 2s 3d^2$, resulting in 890 LS terms and 2048 LSJ levels. Excitation cross sections for the $1s^2 2s^2 2p \ ^2P \rightarrow \ ^4P, ^2D, ^2S$ transitions are in good agreement with experiment. Combined with previous calculations for C and C$^{q+}$ ($q = 25$), sufficient excitation, ionization, and recombination atomic data is now available to generate high quality collisionalradiative coefficients for the entire C isonuclear sequence. [Preview Abstract] 

Q1.00120: Electron Impact ionization cross sections for Hto C isoelectronic series A.K.F. Haque, M.A.R. Patoary, M.A. Uddin, A.K. Basak, B.C. Saha Electron impact ionization crosssections for Hydrogen (H) to Carbon (C) isoelectronic series are calculated using few reliable models [15]. It is observed that these models are not only capable of generating accurate results for various targets over a wide energy domain, ranging from threshold to few MeV but also found successful in describing the most of the experimental findings. In various modeling applications their use will ease the massive data generation needs. \\[4pt] [1] A.K.F. Haque, M.Ismail Hossain, T.I.Talukder, Mahmudul Hasan, M.Alfaz Uddin, A.K.Basak, B.C.Saha, F.B.Malik, Radiation Physics and Chemistry, \textbf{91}, 5059 (2013).\\[0pt] [2] A. K. F. Haque, M. Shahjahan, M. A. Uddin, M. A. R. Patoary, A. K. Basak, B. C. Saha, and F. B. Mali, Physica Scripta, \textbf{81, }045301 (2010).\\[0pt] [3] M. A. Uddin, A. K. F. Haque, A. K. Basak, K. R. Karim, and B. C. Saha, Phys. Rev. A \textbf{72}, 032715 (2005).\\[0pt] [4] M. A. Uddin, M. A. K. Fazlul Haque, A. K. Basak, and B. C. Saha, Phys. Rev. A \textbf{70}, 032706 (2004).\\[0pt] [5] M. A. R. Patoary, M. Alfaz Uddin, A. K. F. Haque, M. Shahjahan, A. K. Basak and B. C. Saha, International Journal of Quantum Chemistry, \textbf{111}, 923 (2011). [Preview Abstract] 

Q1.00121: NearThreshold Dielectronic Recombination Studies of SiLike Ions Jagjit Kaur, Thomas Gorczyca, Nigel Badnell We present results of dielectronic recombination (DR) calculations for the Silike isoelectronic sequence and the important S$^{2+}$ case in particular. A perturbative, multiconfiguration approach is used, and uncertainties in the energy positions of lowlying resonances are investigated. Multiconfiguration HartreeFock calculations are also performed for energy positions of nearthreshold bound and resonance states. This work is motivated by the astrophysical importance of the S$^{2+}$ DR rate in determining the sulfur ionization balance in the Orion nebula, a photoionized plasma corresponding to lowenergy electrons. The computed DR rate coefficients comprise part of the assembly of the DR data base required in the modeling of dynamic finite density plasmas. [Preview Abstract] 

Q1.00122: Laser assisted freefree scattering with variable laser polarization within the scattering plane N.L.S. Martin, C.M. Weaver, B.A. {de}Harak In previous work we reported onephoton emission experiments that examine electronhelium scattering in the presence of an Nd:YAG laser field of 1.17 eV photons, where the laser polarization direction was varied within a plane perpendicular to the scattering plane, and intersecting it along the momentumtransfer direction.\footnote{B.A. deHarak, B.Nosarzewski, M. Siavashpouri, N.L.S. Martin, Phys. Rev. A {\bf90}, 032709 (2014)} The results were perfectly consistent with the KrollWatson\footnote{N. M. Kroll and K. M. Watson, Phys. Rev. A 8, 804 (1973)} approximation. In particular there was no evidence of freefree transitions when the polarization was perpendicular to the momentumtransfer direction, in contrast to the experiments of Wallbank and Holmes.\footnote{M. O. Musa, A. MacDonald, L. Tidswell, J. Holmes, and B. Wallbank, J. Phys. B, 43 (17):175201, 2010} We are in the process of reconfiguring our apparatus to more closely mimic their experiments where the laser polarization was varied {\it within} the scattering plane for one, two, and threephoton absorption. Our preliminary results will be presented. [Preview Abstract] 

Q1.00123: Outofplane ($e,2e$) measurements on He autoionizing levels using a novel electron gun C.M. Weaver, N.L.S. Martin, B.A. deHarak, K. Bartschat In previous work we reported preliminary outofscatteringplane $(e,2e)$ measurements for helium $2\ell2\ell'$ auto\ionizing levels at 150eV incident electron energy and scattering angle 39.2$^\circ$.\footnote{ http://meetings.aps.org/link/BAPS.2014.DAMOP.K1.55} The results were presented as $(e,2e)$ angular distributions energyintegrated over each level, and were compared with our previous experiments and theory at 488eV incident electron energy and scattering angle 20.5$^\circ$.\footnote{B.A. deHarak, K. Bartschat, and N.L.S. Martin, Phys. Rev. Lett. {\bf 100}, 063201 (2008)} The geometry is the same in both cases: ejected electrons are detected in a plane that contains the momentum transfer direction and is perpendicular to the scattering plane, and the momentum transfer is 2.1~a.u. in both cases. It was found that both experiments gave the same angular distributions, but only if instrument function corrections were ignored for the 150eV experiment. We have now installed a new electron gun with a well controlled and narrow spatial profile. We will present new data with instrument function corrections applied. [Preview Abstract] 

Q1.00124: Multiple scattering in laser assisted freefree scattering experiments B.A. deHarak, B.N. Kim, M.R. McCarter, J.L. Savich, A.C. Scherer, C.M. Weaver, N.L.S. Martin Multiple scattering has been repeatedly invoked\footnote{e.g., Nathan Morrison and Chris H. Greene, Phys. Rev. A 86, 053422 (2012)} as a possible explanation for the theoretical difficulties of describing some of the laser assisted freefree experiments reported by Wallbank, et. al\footnote{e.g., B. Wallbank and J. K. Holmes, Phys. Rev. A 48, R2515 (1993)}. Here, we report on experimental results for electronhelium scattering in the presence of an Nd:YAG laser field of 1.17 eV photons where target number densities are varied so that multiple scattering occurs. We compare our results with simple monte carlo simulations that make use of KrollWatson approximation~\footnote{N. M. Kroll and K. M. Watson, Phys. Rev. A 8, 804 (1973)} calculations. [Preview Abstract] 

Q1.00125: Xenon (e,2e) triple differential cross sections Robert D. Mydlowski, H.R.J. Walters, Colm T. Whelan Recently there have been published some interesting experiments on the outer shell of xenon performed in doubly symmetric energy sharing arrangements.\footnote{Kate L Nixon and Andrew James Murray, Phys Rev A, {\bf 85}, 022716, 2012} These experiments present a substantial challenge to theory, not only have we an extremely complex target but the kinematics are such that the key few body effects of exchange, distortion and post collisional electronelectron interaction (pci) and target polarization are likely to be at their strongest and the TDCS will be sensitive to them and their interference. Theoretical results will be presented and compared with experiment [Preview Abstract] 

Q1.00126: Electronimpact ionization and excitation cross sections of C+ excited states Jonathan Pearce, Stuart Loch, Mitch Pindzola, Connor Ballance We present new results of the electronimpact ionization and excitation of C+ excited states. We use both a BreitPauli and term resolved Rmatrix with pseudostates method to compare with available experimental measurements and theoretical values. We extend previous calculations to include all terms in the n=4 shell and ionization from the 1s$^2$2s2p$^2$ configuration. Results are presented for the atomic structure, along with results for both collision strengths and effective collision strengths. The new results will be combined with existing data for the other charge states of C, and used to evaluate generalized collisionalradiative coefficients for the carbon isonuclear sequence. [Preview Abstract] 

Q1.00127: Electron Impact Exciation of Fe IX Swaraj Tayal, Oleg Zatsarinny Transition probabilities and electron impact excitation collision strengths and rates for astrophysically important extreme ultraviolet lines of Fe IX are calculated. The 322 finestructure levels of the $3s^23p^6$, $3s^23p^53d$, $3s3p^63d$, $3s^23p^54s$, and $3s^23p^43d^2$ configurations are included in our calculations. The collision strengths have been calculated using the \hbox{$B$spline} BreitPauli \hbox{$R$matrix} method for all finestructure transitions among the 322 levels. The mass, Darwin, and spinorbit relativistic effects are included in the BreitPauli Hamiltonian in the scattering calculation. The onebody and twobody relativistic operators are included in the multiconfiguration HartreeFock calculations of transition probabilities. Several sets of nonorthogonal spectroscopic and correlation radial orbitals are used to obtain accurate description of Fe IX levels and to represent the scattering functions. The calculated excitation energies are in very good agreement with experiment and represents an improvement over the previous calculations. The present collision strengths show reasonable agreement with the previously available Rmatrix and distortedwave calculations. [Preview Abstract] 

Q1.00128: Simultaneous ionizationexcitation of helium to the 3s, 3p, and 3d states of He$^+$ Oleg Zatsarinny, Klaus Bartschat We extended our work on ionization of helium with simultaneous excitation to the $n=2$ states~[1,2] to include the $n=3$ manifold of the residual ion. This requires the inclusion of pseudostates constructed on the 3s, 3p, and 3d ionic core. We used a parallelized version of the Bspline Rmatrix (BSR) package~[3] to perform a calculation with 1,254 target states, resulting in up to 3,027 coupled channels and matrices of rank up to 200,000 to be diagonalized. The tripledifferential cross section (TDCS) was extracted by the projection method~[1,4]. We obtain excellent agreement with experiment~[5,6] regarding the angular dependence of the TDCS for all kinematical situations available for comparison. Some discrepancies remain for the absolute magnitude. Results for the $n=2$ states are stable and closely agree with previous predictions~[1,2].\\[4pt] [1] O.~Zatsarinny and K.~Bartschat, Phys.\ Rev.\ Lett.~{\bf 107} (2011) 023203.\\[0pt] [2] O.~Zatsarinny and K.~Bartschat, J.~Phys.\ B~{\bf 47} (2014) 061001.\\[0pt] [3] O.~Zatsarinny and K.~Bartschat, Comp.\ Phys~{\bf 174} (2006) 273.\\[0pt] [4] O.~Zatsarinny and K.~Bartschat, J.~Phys.\ B~{\bf 46} (2013) 112001.\\[0pt] [5] S.~Bellm, J.~Lower, and K.~Bartschat, Phys.~Rev.~Lett.~{\bf 96} (2006) 223201.\\[0pt] [6] S.~Bellm {\it et al.}, Phys.~Rev.~A~{\bf 78} (2008) 032710. [Preview Abstract] 

Q1.00129: SPECTROSCOPY, LIFETIMES, OSCILLATOR STRENGTHS 

Q1.00130: Hyperfine structure of the hydroxyl free radical (OH) in electric and magnetic fields Kenji Maeda, Michael L. Wall, Lincoln D. Carr We investigate singleparticle energy spectra of the hydroxyl free radical (OH) in the lowest electronic and rovibrational level under combined static electric and magnetic fields, as an example of heteronuclear polar diatomic molecules. In addition to the finestructure interactions, the hyperfine interactions and centrifugal distortion effects are taken into account to yield the zerofield spectrum of the lowest ${}^2\Pi_{3/2}$ manifold to an accuracy of less than 2kHz. We also examine level crossings and repulsions in the hyperfine structure induced by applied electric and magnetic fields. Compared to previous work, we found more than 10 percent reduction of the magnetic fields at level repulsions in the Zeeman spectrum subjected to a perpendicular electric field. In addition, we find new level repulsions, which we call Starkinduced hyperfine level repulsions, that require both an electric field and hyperfine structure. It is important to take into account hyperfine structure when we investigate physics of OH molecules at microKelvin temperatures and below. [Preview Abstract] 

Q1.00131: THE IRON PROJECT \& Iron Opacity Project: Evidence of increased opacity for solar plasmas W. Eissner,  Hala, S. Nahar, A. Pradhan, J. Bailey The recently reported measurement$^1$ of opacity of iron plasma at high energy density similar to that in the solar convection zone near the boundary of radiative zone shows enhanced continuum, and the integrated opacity is about 7\% higher than that from prediction using the existing Opacity Project (OP) data for photoionization and oscillator strengths. This agrees toward 15\% increment of opacity needed to explain the lower abundance of elements determined by 3D spectral analysis of solar observation. However, our later largescale calculations that included strong resonances due to excitations to highly excited cores states for Fe XVII indicated significant amount of opacity missing in the OP data. We will present our latest findings on the importance of highly excited states on the opacity and how proper inclusion of resonances could enhance the continuum. These will have important impact on the composition of the Sun, the benchmark for astronomical objects. We will also present in progress work under the Iron Project on the collision strengths of Si IX obtained using relativistic effects in the BreitPauli Rmatrix method and transition probabilities of fine structure transitions in Ti I. * Partial support: NSF, DO [Preview Abstract] 

Q1.00132: Further Progress in Data Acquisition and Analysis on the A$^{1}\Sigma^{+}$ and b$^{3}\Pi$ States of NaK Thomas Bergeman, Heather Harker, Amanda Ross, Kara Richter, Joshua Jones, Carl Faust, John Huennekens, Andrey V. Stolyarov, Houssam Salami This work is an extension of work reported at the 2014 DAMOP meeting, with additional data and a more detailed, extensive analysis. Current efforts to produce cold NaK molecules from cold atoms start with production of Feshbach resonances [1] followed by excitation to highlying singlet or triplet states, and then one or twostep possibly stimulated decay to $v$=0 of the $X$ ground state. Efficient use of these processes requires an accurate and detailed knowledge of NaK energy level structure. To meet requirements of current applications we have constructed a model based on direct fits of experimental term values to potentials and spinorbit coupling elements. The model is now complemented by {\it ab initio} calculations of the spinorbit functions.\\[4pt] [1] C.H. Wu, M. Zwierlein et al., PRL {\bf 109}, 085301 (2012). [Preview Abstract] 

Q1.00133: High Precision Spectroscopy of Neutral Beryllium9 Chui Yu Lau, Will Williams We report on the progress of high precision spectroscopy of the 2s2p singlet and triplet states in beryllium9. Our goal is to improve the experimental precision on the energy levels of the 2s2p triplet J$=$0, 1, and 2 states by a factor of 500, 100, and 500 respectively in order to delineate various theoretical predictions. The goal for the 2s2p singlet (J$=$1) state is to improve the experimental precision on the energy level by a factor of 600 as a test of quantum electrodynamics. Our experimental setup consists of an oven capable of 1400C that produces a collimated beam of neutral beryllium9. The triplet states are probed with a 455nm ECDL stabilized to a tellurium210 line. The singlet state is probed with 235nm light from a frequency quadrupled titanium sapphire laser, where the frequency doubled light at 470nm is stabilized to another tellurium210 line. We also present our progress on improving the absolute accuracy of our frequency reference by using an ultrastable/low drift fiber coupled cavity. [Preview Abstract] 

Q1.00134: New Transition Probabilities for Neutral Gadolinium from Boltzmann Analysis of Fourier Transform Spectra David Nitz, Chao Ouyang The recent availability of a large set of absolute transition probabilities for neutral gadolinium (Lawler et al., J. Phys. B: At. Mol. Opt. Phys. 44 (2011) 095001) makes it possible to investigate the relative populations of a large range of upper levels in radiometricallycalibrated Gd spectra. In cases where these populations follow a Boltzmann distribution, the effective temperature which characterizes the distribution provides a means of obtaining new transition probabilities for observable decay branches of nearby levels. While not as accurate as measurements based on branching fractions and lifetimes, this method can be applied to levels whose lifetimes are not known and does not require accounting for all of the decay branches. We are analyzing Fourier Transform spectra of Gd from the National Solar Observatory data archive at Kitt Peak used by Lawler et al. in their study and have identified two broadband spectra (9000  24000 cm$^{\mathrm{1}})$ which exhibit Boltzmann behavior for energy levels in the range 17750  36650 cm$^{\mathrm{1}}$. These analyses and a summary of new transition probabilities obtained from them to date will be presented. [Preview Abstract] 

Q1.00135: La Saturated Absorption Spectroscopy for Applications in Quantum Information Patrick Becker, Liz Donoghue, Kristina Dungan, Jackie Liu, Steven Olmschenk Quantum information may revolutionize computation and communication by utilizing quantum systems based on matter quantum bits and entangled light. Ions are excellent candidates for quantum bits as they can be wellisolated from unwanted external influences by trapping and laser cooling. Doublyionized lanthanum in particular shows promise for use in quantum information as it has infrared transitions in the telecom band, with low attenuation in standard optical fiber, potentially allowing for long distance information transfer. However, the hyperfine splittings of the lowest energy levels, required for laser cooling, have not been measured. We present progress and recent results towards measuring the hyperfine splittings of these levels in lanthanum by saturated absorption spectroscopy with a hollow cathode lamp. [Preview Abstract] 

Q1.00136: High Resolution Electron Spectroscopy with TimeofFlight Spectrometers Bertold Kr\"assig, Elliot P. Kanter We have developed a parametrization based on raytracing calculations to convert electron timeofflight (eTOF) to kinetic energy for the spectrometers of the LCLSAMO end station at SLAC National Accelerator Laboratory [C. Bostedt {\em et al}, J. Phys. B {\bf 46}, 164003 (2013)]. During the experiments the eTOF detector signals are recorded as digitized waveforms for every shot of the accelerator. With our parameterization we can analyze the waveforms online and convert detector hit times to kinetic energies. In this way we accumulate histograms with equally spaced bins in energy directly, rather than {\em a posteriori} converting an accumulated histogram of equally spaced flight times into a histogram of kinetic energies with unequal bin sizes. The parametrization is, of course, not a perfect replica of the ray tracing results, and the ray tracing is based on nominal dimensions, perfect alignment, detector response, and knowledge of time zero for the timeofflight. In this presentation we will discuss causes, effects, and remedies for the observed deviations. We will present highresolution results for the Ne $KLL$ Auger spectrum that has been well studied and serves as a benchmark for our analysis algorithm. [Preview Abstract] 

Q1.00137: Theoretical and experimental study of subDoppler DAVLL for D1 lines of $^{87}$Rb and $^{85}$Rb atoms Gyeong Won Choi, Heung Ryoul Noh A theoretical and experimental study of lineshapes in subDoppler DAVLL (dichroic atomic vapor laser lock) for the D1 transition line of $^{87}$Rb and $^{85}$Rb atoms was presented. The induced dichroism in a rubidium vapor due to a linearly polarized pump beam was measured using a counterpropagating probe beam in the presence of an external magnetic field. We compared measured subDoppler DAVLL spectra with calculated results using rate equations, and found a good agreement between them. We also studied the coherence effects in the lineshape of subDoppler DAVLL and found that the branching ratio played an important role in resulting significant effect of the coherence term. [Preview Abstract] 

Q1.00138: Microwave transitions between pair states composed of two Rb Rydberg atoms Jeonghun Lee, Tom Gallagher Microwave transitions between pair states composed of two Rb Rydberg atoms in a magnetooptical trap are investigated. Our current interest is the transition from ndnd to (n+1)d(n2)f states. This transition is allowed because the dipoledipole induced configuration interaction between the ndnd state and the energetically close (n+2)p(n2)f state admixes some of the latter state into the former. The resonance frequencies of the ndnd(n+1)d(n2)f transitions for n=35 to 42 have been measured and found to agree well with the calculated values. In addition, the power shifts of the resonance frequencies have been measured for n=35 to 42. The dependence of the fractional population transfer from the ndnd to (n+1)d(n2)f states on the microwave field strength and atomic density has been measured and can be compared to a simple theoretical model. This work has been supported by the Air Force Office of Scientific Research. [Preview Abstract] 

Q1.00139: Characterization of a partiallystabilized frequency comb M.E. Gold Dahl, Alex Erikson, Daniel Woodbury, Scott Bergeson We present measurements of wellknown frequency intervals in Cs, Rb, and Ca. These measurements are used to determine the accuracy of a partiallystabilized ti:sapphire frequency comb. One mode of our frequency comb is offsetlocked to a Rbstabilized diode laser. The comb's repetition rate is counted but not locked. A second laser is used to probe wellknown atomic transitions in Cs, Rb, and Ca. We describe our offset locking and scanning techniques and demonstrate a frequency precision of 10 kHz in a 30 second measurement time. The accuracy of our laser frequency interval measurements is approximately 40 kHz. However, cellbased frequency references can be off by several hundred kHz. [Preview Abstract] 

Q1.00140: Comparison of absorption, fluorescence, and polarization spectroscopy of atomic rubidium Seth Ashman, Cayla Stifler, Joaquin Romero An ongoing spectroscopic investigation of atomic rubidium utilizes a twophoton, singlelaser excitation process. Transitions accessible with our tunable laser include $5P_{1/2} \left( {F'} \right)\leftarrow 5S_{1/2} \left( F \right)$ and $5P_{3/2} \left( {F'} \right)\leftarrow 5S_{1/2} \left( F \right)$. The laser is split into a pump and probe beam to allow for Dopplerfree measurements of transitions between hyperfine levels. The pump and probe beams are overlapped in a counterpropagating geometry and the laser frequency scans over a transition. Absorption, fluorescence and polarization spectroscopy techniques are applied to this basic experimental setup. The temperature of the vapor cell and the power of the pump and probe beams have been varied to explore line broadening effects and signaltonoise of each technique. This humble setup will hopefully grow into a more robust experimental arrangement in which double resonance, twolaser excitations are used to explore hyperfine state changing collisions between rubidium atoms and noble gas atoms. Rbnoble gas collisions can transfer population between hyperfine levels, such as $5P_{3/2} \left( {F'=3} \right)\buildrel {Collision} \over \longleftarrow 5P_{3/2} \left( {F'=2} \right)$, and the probe beam couples $7S_{\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern\nulldelimiterspace}\!\lower0.7ex\hbox{$2$}} \left( {F''=2} \right)\leftarrow 5P_{3/2} \left( {F'=3} \right)$. Polarization spectroscopy signal depends on the rate of population transfer due to the collision as well as maintaining the orientation created by the pump laser. Fluorescence spectroscopy relies only on transfer of population due to the collision. Comparison of these techniques yields information regarding the change of the magnetic sublevels, $m_{F} $, during hyperfine state changing collisions. [Preview Abstract] 

Q1.00141: Measurement of the Stark shift of the 6s$^{2}$S$_{1/2}$ $\to$ 7p$^{2}$P$_{\mathrm{J}}$ transitions in atomic cesium George Toh, D. Antypas, D.S. Elliott We report measurements of the Stark shift of the cesium 6s$^{2}$S$_{1/2} \to $ 7p$^{2}$P$_{1/2}$ and 6s$^{2}$S$_{1/2}$ $\to $ 7p$^{2}$P$_{3/2}$ transitions at $\lambda = $ 459 and 456 nm, respectively, in an atomic beam. From these measurements, we determine the static scalar polarizability for both 7P$_{\mathrm{J}}$ states and the tensor polarizability for the 7P$_{3/2}$ state. The fractional uncertainty of the scalar polarizabilities is $\sim $0.18{\%}, while that of the tensor term is 0.7{\%}. These measurements allow a precise determination of the reduced radial matrix elements \textless 7P$_{1/2}$\textbar \textbar r\textbar \textbar 6D$_{3/2}$\textgreater $=$ 17.92 (3) a$_{\mathrm{0}}$ and \textless 7P$_{3/2}$\textbar \textbar r\textbar \textbar 6D$_{5/2}$\textgreater $=$ 24.28 (6) a$_{\mathrm{0}}$, providing a sensitive test and critical confirmation of theoretical models of the Cs atom, which has played a central role in parity nonconservation measurements. [Preview Abstract] 

Q1.00142: Inexpensive, pocketsized LEDbased fluorometer for undergraduate teaching laboratories and inthefield chemical detection Gage Tiber, Partha Basu, Theodore A. Corcovilos Fluorometry is a standard experimental technique for the detection of chemical compounds in solution. Excitation light is absorbed by a sample and then longerwavelength light is emitted. Typical laboratory fluorometers are large and expensive, making them poorly suited for field work and teaching laboratories. We present a simple batterypowered fluorometer built with offtheshelf components and a 3Dprinted body. The light sources are userreplaceable light emitting diodes (LEDs). Two independent light sources of different wavelengths allow ratiometric measurements of the sample. The detectors are photodiodes with interchangeable dielectric FabryPerot stack spectral filters. The light gathering optics are designed using nonimaging optics principles to maximize the amount of detected fluorescence light. We present the design of the device and demonstrate the sensitivity using a molecular detector\footnote{Marbella, L., et al.{} Angew.{} Chem. 121, 4056 (2009).} of Pb$^{2+}$ ions in solution. The absorption and emission wavelengths of the detector molecule change from 415 nm and 465 nm, resp., in the absence of Pb$^{2+}$ to 389 nm and 423 nm, resp., in the presence of Pb$^{2+}$. The estimated sensitivity of the fluorometer with this molecular detector is a few p.p.b. [Preview Abstract] 

Q1.00143: Spectral data for Flike ions: Ca, Ti, Cr, Ni Gultekin Celik, Sule Ates, Sultana Nahar Transition Probabilities, oscillator strengths and lifetimes have been determined for fluorine like Ca, Ti, Cr, and Ni through atomic structure calculations in the relativistic BreitPauli approximation. These transition parameters are needed for spectral analysis of ironpeak elements in astrophysical objects. We employed the code SUPERSTRUCTURE. The results are compared with available theoretical and experimental results. Good agreement with results in the literature has been found for most cases. [Preview Abstract] 

Q1.00144: Electronic Transition Dipole Moment and Radiative Lifetime Calculations of Sodium Dimer IonPair States Aydin Sanli, Bediha Beser, John Edwardson, Sylvie Magnier, Ergin Ahmed, Marjatta Lyyra Alkali dimer M2 and alkali hydride MH molecular electronic states with ionpair character are known to exhibit multiple minima and shoulders in their potential energy curves. This exotic behavior of the of the 1$\Sigma $g$+$ symmetry states is caused by an avoided crossing of the zeroorder covalent and ionic (M$+ \quad + \quad$ M$$) potential energy curves. We present a computational study of lifetimes and transition dipole moment matrix elements for the sodium dimer ionpair states of 1$\Sigma $g$+$ symmetry. We report here the ab initio calculated electric transition dipole moments between the n 1$\Sigma $g$+$ and the A1$\Sigma $u$+$ states , that vary strongly as a function of internuclear distance. In addition, we have calculated the radiative lifetimes, $\tau $, of these ionpair states of and compared them with the experimental results from literature when available. [Preview Abstract] 

Q1.00145: Photodetachment Spectroscopy of La$^{}$: Resonances and Thresholds C.W. Walter, N.D. Gibson, C. Crocker, K.A. Dungan, B.R. Matola The negative ion of lanthanum, La$^{}$, has the richest bound state spectrum ever observed for an atomic negative ion [1], and it has been proposed as perhaps the best candidate for laser cooling of a negative ion [2]. In the present experiments, photodetachment thresholds and transitions between bound states of La$^{}$ are investigated using tunable infrared spectroscopy. The relative signal for neutral atom production was measured with a crossed ionbeamlaserbeam apparatus over the photon energy range 290900 meV. The spectrum reveals at least 14 sharp resonance peaks due to transitions to either bound states of the negative ion or quasibound states in the continuum. Multiple photodetachment thresholds are also observed, providing information on the binding energies for some states of La$^{}$. \\[4pt] [1] C. W. Walter \textit{et al.}, \textit{Phys. Rev. Lett.} \textbf{113}, 063001 (2014) ; [2] S.M. O'Malley and D.R. Beck, \textit{Phys. Rev. A} \textbf{81}, 032503 (2010). [Preview Abstract] 

Q1.00146: POSTDEADLINE POSTERS 

Q1.00147: 532nm intensitymodulated optical lattice for driving RydbergRydberg transitions Jamie MacLennan, Kaitlin Moore, Andira Ramos, Georg Raithel We present progress towards implementing an experiment to make a precision measurement of the Rydberg constant using circularstate Rydberg atoms. An independent measurement of the Rydberg constant will contribute to solving discrepancies in fundamental physics, most notably the ``proton radius puzzle'' [1]. The experiment relies on driving a circular to nearcircular, n $=$ 51 to 53 RydbergRydberg transition.~This transition was chosen because it is insensitive to nuclear charge distribution and firstorder Stark and Zeeman effects, yielding less uncertainty in a Rydberg constant measurement. The Rydberg atoms are trapped in a 532nm~optical lattice, which is intensitymodulated so that its temporal harmonics drive the microwavefrequency transitions, socalled ``ponderomotive spectroscopy.'' We have previously demonstrated ponderomotive spectroscopy using 1064nm~light modulated by a fiberbased electrooptic modulator (EOM) [2]. Here, the 532nm light offers the benefit of a ``magic wavelength'' for the transition. Finding a method to prepare a tunable, highpower, intensitymodulated optical lattice at 532 nm presents a substantial challenge. Here, we report on progress in overcoming this challenge as well as on other recent experimental developments.\\[4pt] [1] R. Pohl, et al., Nature, 466, 213 (2010).\\[0pt] [2] K.R. Moore, S.E. Anderson, G. Raithel, Nat. Commun., 6 (2015). [Preview Abstract] 

Q1.00148: Spatial Relevancies of Hybrid Systems Relates to Superfluid Fatahillah HidajatullahWidastra After S/F hybrid system from Martin Lange, of spatial modulation SuperconductorElectromagnet hybrids superconductor producing studies conclusion, for superconductor at large $H $and/or $T $(i.e close to the \textbf{phase transition }line ), when the superfluid densitiy tends to 0[GW Ataklti, \textit{et.al}, Supercond. Sci. Technol. \textbf{25 }( 2012 ) ]. Further as for He$^{3}$B superfluid ``\textit{testing ground''}, after sought \textbf{extensometer }for every materials testing application from \textless \underline {www.zwick.com} \textgreater , in K Matsumoto:\textbf{''Flux pinning Engineering for Application of HTS''}, 2013 quote Higgs boson , whereas it plays role as similar phenomena of Meissner effect, both involves magnet levitating. Accompanying Gosowong vein, US {\$} 16. 3 Million costed studyreport who said the toxic waste also endangering biodiversity[Dini Septanti: \textbf{``The BUYAT Case: Straddling between Environmental Securitization {\&} Desecuritization'' }, herewith proposed the ``complexity systems'' comparison comprises also phase transition {\&} ``directed polymer'' notions of JP Bouchaud, \textit{et.al}:\textbf{''Wealth condensation in a simple model of economy''.} [Preview Abstract] 

Q1.00149: From Planck Constant to Isomorphicity Through Justice Paradox Widastra HidajatullahMaksoed Robert E. Scott in his \textbf{``Chaos theory and the Justice Paradox'', }William {\&} Mary Law Review, v 35, I 1, 329 (1993) wrotes''\textellipsis As we approach the 21st Century, the signs of social disarray are everywhere. Social critics observe the breakdown of core structure  the nuclear family, schools, neighborhoods {\&} political groups''. For completions for ``soliton'' first coined by Morikazu TODA, comparing the ``Soliton on ScottRussell aqueduct on the Union Canal near HeriotWATT University, July 12, 1995 to Michael Stock works: \textbf{``a Fine WATTBalance: Determination of Planck constant {\&} Redefinition of Kilogram'', }January 2011, we can concludes the inherencies between `chaos' {\&} `soliton'. Further through ``string theory'' from Michio KAKU sought statements from Peter Mayr: \textbf{Stringy world brane {\&} Exponential hierarchy'', }JHEP 11 ( 2000): ``if the 5brane is embedded in flat 10D space time, the 6D Planck mass on the brane is \textbf{infinite'' } who also describes the relation of isomorphicity {\&} ``string theory'', from whom denotes the \textbf{smart city.} Replace this text with your abstract body. [Preview Abstract] 

Q1.00150: Differential Measurements for Positron Impact Ionization of Argon D.W. Mueller, R. Boadle, S. Armitage, A. Dorn, S.J. Buckman, J.P. Sullivan Differential triple coincidence measurements for positron impact ionization can provide indepth insight into antimatter interactions with matter. We present the results of our recent measurements for 190eV positrons incident on Argon, leading to ionization. We present our early results which are differential for both the ejected electron and scattered positron in energy and angle. In addition to the large angle electron scattering, a smaller peak in the forward direction at 1/2 the scattered positron velocity is apparent. This peak suggests that these electrons are traveling on the Wannier ridge. [Preview Abstract] 

Q1.00151: Manipulation and control of a bichromatic lattice Claire Thomas, Thomas Barter, Severin Daiss, Zephy Leung, Dan StamperKurn Recent experiments with ultracold atoms in optical lattices have had great success emulating the simple models of condensed matter systems. These experiments are typically performed with a single site per unit cell. We realize a lattice with up to four sites per unit cell by overlaying an attractive triangular lattice with a repulsive one at twice the wavelength. The relative displacement of the two lattices determines the particular structure. One available configuration is the kagome lattice, which has a flat energy band. In the flat band all kinetic energy states are degenerate, so we have the opportunity to explore a regime where interactions dominate. This bichromatic lattice requires careful stabilization, but offers an opportunity to manipulate the unit cell and band structure by perturbing the lattices relative to one another. I will discuss recent progress. [Preview Abstract] 

Q1.00152: Probing Fermi Superfluids with SpinOrbit Coupling Via SpinSpin Correlation Functions Brandon Anderson, Rufus Boyack, ChienTe Wu, K. Levin Systems of fermions with spinorbit coupling (SOC) have emerged as an exciting area of research in recent years, in large part due to the possibility of observing topological phases. By applying an outofplane Zeeman field, a fermi superfluid with SOC can be driven through a topological phase transition, analogous to the the topological transition found in $p+ip$ superconductors. What is frequently missed in these topological transitions is beyond meanfield effects. We establish and characterize fluctuations associated with the standard mean field equations of the superfluid instability. This introduces bosonic degrees of freedom, at a level beyond Gaussian fluctuations, that must condense for the fermionic superfluid to be stable. We present a consistent treatment of these fluctuations in regards to both the condensate as well as in twobody correlation functions. In this context we study spinspin correlation functions that reveal interesting structure associated with SOC admixed with superfluidity, including signatures of the topological phase transition. [Preview Abstract] 

Q1.00153: Motional resonance enhanced artificial atomic spinorbit coupling Lingna Wu, Xinyu Luo, ZhiFang Xu, Masahito Ueda, Ruquan Wang, Li You Atomic spinorbit coupling (SOC) represents an important type of synthetic gauge fields actively pursued in quantum simulation studies. Recently, different schemes based on pulsed or periodic modulating gradient magnetic field (GMF) are proposed and implemented to synthesize one dimensional (1D) SOC in a spinor atomic BoseEinstein condensate (BEC). This study provides theoretical understanding and experimental confirmation that the strength of SOC is enhanced making use of motional resonance associated with atomic center of mass in a harmonic trap. In addition to enable extra tunability and flexibility of gradient magnetic field based schemes for synthesizing atomic SOC, the findings we present also shed light on experimental efforts towards synthesizing twodimensional (2D) atomic SOC. [Preview Abstract] 

Q1.00154: Efficient Photon Collection from a Nitrogen Vacancy Center in a Circular Bullseye Grating in Diamond Edward Chen, Luozhou Li, Jiabao Zheng, Sara Mouradian, Florian Dolde, Tim Schroder, Sinan Karaveli, Matthew Markham, Daniel Twitchen, Dirk Englund Efficient collection of the broadband fluorescence from the diamond nitrogen vacancy (NV) center is essential for a range of applications in sensing and quantum information processing. Here, we introduce a circular `bullseye' diamond grating which enables a collected photon rate of 2.7$\pm $0.9 x 10$^{6}$ counts per second from a single NV with a spin coherence time of 1.7$\pm $0.1 ms. Backfocalplane studies indicate efficient redistribution of the NV photoluminescence into lowNA modes by the gratings. Compared to other geometries with high collection efficiencies, the planar structure of the bullseye grating allows for direct transfer onto different substrates for device integration with other optical components, such as electricallygated onchip photon detectors and optical fiber facets. For narrowband applications ($\Delta \lambda $/$\lambda $\textless 0.03) the collection efficiency can be optimized to as high as 90{\%} of the total dipole emission power within an NA$=$1.5. This makes the bullseye geometry particularly useful for collection of the zerophonon line, e.g. for spinphoton entanglement.\footnote{Pfaff, W., et al. Science 345.6196 (2014).} [Preview Abstract] 

Q1.00155: ABSTRACT WITHDRAWN 

Q1.00156: InSitu Lattice Polarization Measurement by Atomic Wave Scattering Felix Schmidt, Michael Bauer, Farina Kindermann, Tobias Lausch, Daniel Mayer, Artur Widera Optical dipole traps and lattices have become indispensable tools in atomic physics and atom optics. Especially the accurate alignment of the beam polarization is crucial, because a deviation from purely linear polarization will result in state dependent ACstark vector light shifts, which are proportional to the atoms' magnetic $m_F$ substates. Such shifts can be either utilized as a tool for state dependent atomic transport and the creation of artificial gauge fields, or, in contrast, could cause unwanted dephasing in quantum information processing and spectroscopic experiments. Here, we present an insitu measurement method of an optical lattice's polarization purity by employing the KapitzaDirac effect  the scattering of atoms by a standing light wave: We create a Rubidium87 (Rb) BEC and shine in an optical lattice at 790 nm that is tuned in between the $D_1$ and $D_2$ lines of Rb. At this wavelength, the scalar dipole potentials of both lines counteract and ideally cancel out, yielding a high sensitivity to vector light shifts for different $m_F$ states. By analysing the scattering of Rb atoms in the residual potential for different $m_F$ states, we can extract the lattice polarization with high accuracy below $10^{3}$. [Preview Abstract] 

Q1.00157: Generation of continuouswave 194 nm laser for mercury ion optical frequency standard Hongxin Zou, Yue Wu, Guozhu Chen, Yong Shen, Qu Liu 194 nm continuouswave (CW) laser is an essential part in mercury ion optical frequency standard. The continuouswave tunable radiation sources in the deep ultraviolet (DUV) region of the spectrum is also serviceable in highresolution spectroscopy with many atomic and molecular lines. We introduce a scheme to generate continuouswave 194 nm radiation with SFM in a Beta Barium Borate (BBO) crystal here. The two source beams are at 718 nm and 266 nm, respectively. Due to the property of BBO, critical phase matching (CPM) is implemented. One bowtie cavity is used to resonantly enhance the 718 nm beam while the 266 nm makes a single pass, which makes the configuration easy to implement. Considering the walkoff effect in CPM, the cavity mode is designed to be elliptical so that the conversion efficiency can be promoted. Since the 266 nm radiation is generated by a 532 nm laser through SHG in a BBO crystal with a large walkoff angle, the output mode is quite nonGaussian. To improve mode matching, we shaped the 266 nm beam into Gaussian modes with a cylindrical lens and iris diaphragm. As a result, 2.05 mW 194 nm radiation can be generated. As we know, this is the highest power for 194 nm CW laser using SFM in BBO with just single resonance. [Preview Abstract] 

Q1.00158: DiodePumped Dye Laser Using a Tapered Optical Fiber Brian Patterson, James Stofel, Elliot Myers, Randy Knize We describe the construction of a simple dye laser based on a singlemode optical fiber. Light from a 120mW laser diode ($\lambda \quad =$ 520 nm) is launched into the fiber. The fiber is tapered to a diameter of approximately 1 $\mu $m and placed in Rhodamine 6G laser dye. The pump light interacts with the gain medium through the evanescent field outside the fiber causing stimulated emission, which couples back into the fiber. Mirrors on each end of the fiber provide the necessary feedback for lasing, and a grating is used to narrow the spectral output. We characterize the lasing threshold and output spectrum of the laser. This has been a good project for undergraduate students to learn about lasers and optics. [Preview Abstract] 

Q1.00159: High precision variational calculations of fewelectron atoms Sergiy Bubin High precision calculations of energy levels and other properties of small atoms and ions have been a subject of fruitful interplay between the experiment and theory. However, most calculation of spectroscopic accuracy, until recently, have been possible only for two and threeelectron systems. In this talk I will report on progress toward performing high accuracy calculations of larger atomic systems (up to foursix electrons). The results of benchmark quality are attainable with the use of variational expansions in terms of allparticle explicitly correlated Gaussians, whose nonlinear variational parameters are extensively optimized. I will demonstrate what level of accuracy is available today for fewelectron atoms and discuss the issues that must be overcome in order to extend the capability of the method to even larger systems. [Preview Abstract] 

Q1.00160: Memorybuiltin quantum cloning in a hybrid solidstate spin register Weibin Wang, Chong Zu, Li He, Wengang Zhang, Luming Duan As a way to circumvent the quantum nocloning theorem, approximate quantum cloning protocols have received wide attention with remarkable applications. Copying of quantum states to memory qubits provides an important strategy for eavesdropping in quantum cryptography. We report an experiment that realizes cloning of quantum states from an electron spin to a nuclear spin in a hybrid solidstate spin register with nearoptimal fidelity. The nuclear spin provides an ideal memory qubit at room temperature, which stores the cloned quantum states for a millisecond under ambient conditions, exceeding the lifetime of the original quantum state carried by the electron spin by orders of magnitude, and making it an ideal memory qubit. Our experiment is based on control of an individual nitrogen vacancy (NV) center in the diamond, which is a diamond defect that attracts strong interest in recent years with great potential for implementation of quantum information protocols. [Preview Abstract] 

Q1.00161: Radiofrequency induced Feshbach resonances Yijue Ding, Jose D'Incao, Chris Greene We elaborate a set of tools that allow us to analyze the possible ways in which a Feshbach resonance can be induced by applying an external oscillating magnetic field. This possibility can allow one to develop the simultaneous control of multiple Feshbach resonances and greatly expand the range of new phenomena that can be explored in ultracold homonuclear and heteronuclear quantum gases. We use the Floquet representation in order to explore such scenarios both numerically and analytically via the extension of MQDT to external oscillating fields. [Preview Abstract] 

Q1.00162: Tuneout Wavelength of $\mathbf{^{4}}$He for the $\mathbf{1s2s}$ $\mathbf{^{3}}$S  $\mathbf{1s3p}$ $\mathbf{^{3}}$P Transition Jacob Manalo, Gordon Drake Tuneout wavelengths are those where the dynamic polarizability of an atom is zero. Several applications include laser cooling, atomic clocks and quantum information, all for the Group II atoms [1]. Of the Group II's, helium is a useful subject as it is the simplest atom of two electrons. According to Mitroy and Tang, the tuneout wavelength closest to the $1s2s$ $^{3}S$  $1s3p$ $^{3}P$ transition for metastable helium can serve as a useful low energy probe of atomic structure [2]. Our calculation of this wavelength, employing a full Hylleraas basis set as well as mass polarization for $^4$He, is 0.11030082982551(1) in reduced mass atomic units. In order to measure this tuneout wavelength, an interferometer is needed [2]. Methods of using laser beams as waveguides for matter waves have been explored, and such techniques can be applied to interferometry as stated by Baldwin et al. [3]. Our future calculations will include relativistic and QED corrections.\\[4pt] [1] B. Arora, M. S. Safronova, and C.W. Clark, Phys. Rev. A \textbf{84}, 043401 (2011).\newline [2] J. Mitroy and L.Y. Tang, Phys. Rev. A \textbf{88}, 052515, (2013).\newline [3] R. G. Dall, S. S. Hodgman, M. T. Johnsson, K. G. H. Baldwin, and A. G. Truscott, Phys. Rev. A \textbf{81}, 011602(R) (2010). [Preview Abstract] 

Q1.00163: Visualizing Magnetism with Optical Ferrofluid Cells Michael Snyder a novel technique for the visualization of magnetic fields. The ferrofluid cells are made up of two optically flat windows with a layer of Fe3O4/Fe2O3 ferrofluid between the glass. Using different magnet configurations and lighting, highly structured pictures are obtained of one of the universes forces. Characterized as the magnetooptic Kerr/displacement current effect on self assembled micrometer sized helical rods of Fe304/Fe203. [Preview Abstract] 

Q1.00164: ABSTRACT WITHDRAWN 

Q1.00165: Hamiltonian Tomography by Dynamical Decoupling ShengTao Wang, DongLing Deng, LuMing Duan The identification and verification of quantum dynamics is essential for quantum information and communication tasks and for benchmarking quantum simulation. Hamiltonian tomography for a general manybody system is difficult due to the massive entanglement generated in the manybody evolution. In this paper, we tackle this problem and show that techniques from dynamical decoupling can be exploited to reduce the formidable task to simple one or twospin tomography in a general manyqubit system. All parameters in the Hamiltonian can be retrieved and the required number of measurements scales at most quadratically with the system size. We further demonstrate numerically that the scheme is robust to various sources of errors typically present in experiments. We expect the scheme to be readily implementable in many experimental platforms. [Preview Abstract] 

Q1.00166: Cascade Raman sidebands generation and orbital angular momentum relations for paraxial beam modes James Strohaber, Hans Schuessler, Alexandre Kolomenskii, Feng Zhu In this work, the nonlinear parametric interaction of optical radiation in various transverse modes in a Ramanactive medium is investigated both experimentally and theoretically. Verification of the orbital angular momentum algebra (OAMalgebra) [Strohaber et al., Opt. Lett. 37, 3411 (2012)] was performed for highorder Laguerre Gaussian modes. It was found that this same algebra also describes the coherent transfer of OAM when InceGaussian modes were used. New theoretical considerations extend the OAMalgebra to even and odd Laguerre Gaussian, and Hermite Gaussian beam modes through a change of basis. The results of this work provide details in the spatiotemporal synthesis of custom broadband pulses of radiation from Raman sideband generation. [Preview Abstract] 

Q1.00167: Fragmented Manybody States of Spin2 Bose Gas HsiangHua Jen, Sungkit Yip For a spin1 Bose gas with ``antiferromagnetic interaction'' in zero magnetic field, the exact ground state is fragmented, consisting twoparticle spinsinglets for even number of particles. While its meanfield (MF) state is polar, it is claimed that the exact ground state can be viewed as an angular average over its MF polar state, as a direct analogy to, e.g., the generation of Fock states by averaging over the relative phase of the coherent state in the case of a double well. This picture has become the common belief in the community. In this work, we demonstrate how angularaveraged MF polar states are unable to construct the exact manybody ground states in the spin2 case. That the angular averaged MF states is the exact ground state is simply a coincidence in the spin1 system. We address the inapplicability of the angularaveraging process, and further investigate the limitations on obtaining the exact manybody state from angular averaging of the MF cyclic state. We also show how the angularaveraged MF state deviates from the exact eigenstate by studying the twoparticle density matrices. Our results overturn the common belief that the exact ground states are equivalent to angularaveraged MF states, and give a broader perspective on fragmented manybody bosonic ground states. [Preview Abstract] 

Q1.00168: Cold Lithium Atom Interferometer Kayleigh Cassella, Eric Copenhaver, Chen Lai, Paul Hamilton, Brian Estey, Yanying Feng, Holger Mueller Atom interferometers often use heavy alkali atoms such as rubidium or cesium. In contrast, interferometry with light atoms offers a larger recoil velocity and recoil energy, yielding a larger interference signal. This would allow for sensitive measurements of the fine structure constant, gravity gradients and spatially varying potentials. We have built the first lightpulse coldatom interferometer with lithium in a MachZehnder geometry based on short (100 ns), intense (2.5 W/cm$^{2})$ pulses. We initially capture approximately 10$^{7}$ lithium atoms at a temperature of about 300 $\mu $K in a magnetooptical trap. To perform interferometry, we couple the $F=$1 and $F=$2 hyperfine levels of the ground state with a sequence of twophoton Raman transitions, reddetuned from lithium's unresolved 2P$_{3/2}$ state. Cold lithium atoms offer a broad range of new possibilities for atom interferometry including a large recoil velocity and a fermionic and bosonic isotope. Lithium's isotopes also allow for independent measurements of gravity thus constraining the equivalence principle violations predicted by the StandardModel Extension. In the near future, we plan to perform a recoil measurement using a RamseyBord\'{e} interferometer. [Preview Abstract] 

Q1.00169: Photoassociation spectroscopy of longrange molecular states below the $2\textrm{s}+3\textrm{p}$ $^{6}\textrm{Li}_{2}$ asymptote Christian Gross, Saptarishi Chaudhuri, Jaren Gan, Kai Dieckmann We present photoassociation spectra of highlying vibrational states of the interatomic potentials correlating to the $2\textrm{s}+3\textrm{p}$ asymptote of $^{6}\textrm{Li}_{2}$. Starting from an atomic cloud in a magnetooptical trap we first drive a freetobound transition into a molecular bound state using a tunable ultraviolet laser. Thereafter we ionize these longrange molecules using a $532\,$nm laser and detect the resulting ions with a channeltron. We determine the absolute positions of the transitions with MHz precision utilizing a frequency comb based calibration. Lithium dimers are extensively studied theoretically using various models and methods. Spectroscopic measurements are crucial to test and benchmark these methods and are available for various electronic states and internuclear distances of $^{6}\textrm{Li}_{2}$ molecule. Our study provides the first experimental observation of longrange states of the $2\textrm{s}+3\textrm{p}$ asymptote of $^{6}\textrm{Li}_{2}$. [Preview Abstract] 

Q1.00170: Laser frequency stabilization by light shift of opticalmagnetic double resonances Yuanzhi Zhan, Xiang Peng, Zaisheng Lin, Wei Gong, Hong Guo This work adopts the light shift of opticalmagnetic double resonance frequency in metastablestate $^{\mathrm{4}}$He atoms to lock the laser center frequency to the magic point. At this magic frequency, both the leftcircularly and rightcircularly optical pumping processes will give the same value of opticalmagnetic double resonance. With this method and after locking, experimental results show that the laser frequency fluctuation is dramatically reduced to 2.79 MHz in 3600 seconds, comparing with 34.1 MHz drift in the free running mode. In application, with the locked magic laser frequency, the heading error for laser pumped $^{\mathrm{4}}$He magnetometer can be eliminated much. [Preview Abstract] 

Q1.00171: Scalable Microwave Addressing of Trapped Ion Qubits at Faulttolerant Error Levels Diana Prado Lopes Aude Craik, Norbert Linke, David Allcock, Thomas Harty, Martin Sepiol, Derek Stacey, Andrew Steane, David Lucas We present results obtained with a twozone, scalable prototype surfaceelectrode ion trap for storing and individually addressing memory qubits. The trap has 4 integrated microwave electrodes per zone, designed to provide enough degrees of freedom for independent, parallel control of the microwave field amplitude, phase and polarization at each ion. In a demonstration experiment, we use two trap electrodes, one in each zone, to drive Rabi flops in a Calcium43 ion trapped in the zone we wish to address, while nulling the microwave field in the neighbor zone. We measure Rabi frequency ratios between the addressed and nulled zones of up to 1400, implying that spinflip errors of order $10^{6}$ are achievable. We also demonstrate polarization control of the microwave field by selectively driving one of two neardegenerate transitions out of the qubit states, one of which is driven by $\sigma^{+}$ polarization and the other by $\sigma^{}$ polarization. We null the $\sigma^{+}$ component of the microwave field at the ion and measure a Rabi frequency ratio of $\approx 350$ between the $\sigma^{}$ and $\sigma^{+}$ transitions. Finally, a new design concept for scalable microwave surfaceelectrode ion traps is presented and progress on the nextgeneration prototype is reported. [Preview Abstract] 

Q1.00172: Measuring the fine structure constant with Bragg diffraction and Bloch oscillations Chenghui Yu We have demonstrated a new scheme for atom interferometry based on largemomentum transfer Bragg beam splitters and Bloch oscillations. In this new scheme, we have achieved a resolution of $\delta\alpha/\alpha=0.25ppb/\sqrt(25h/\tau)$ in the fine structure constant measurement, which gives up to 4.4 million radians of phase difference between freely evolving matter waves. We have also suppressed our major phase shift caused by Bragg diffraction by more than 1000fold, as well as other systematic errors, including the Zeeman effect phase shift, which are known in similar atom interferometer experiments. [Preview Abstract] 

Q1.00173: Entangling transportable neutral atoms via local spinexchange Adam Kaufman, Brian Lester, Niclas Luick, Cindy Regal Building on our recent work preparing indistinguishable atoms and performing an atomic HongOuMandel experiment~[1], we now use these techniques to create controlled spinentanglement between two neutral atoms. We demonstrate the full toolset for using local spinexchange to create nonlocal entanglement. Starting with two spatially separated atoms, we controllably apply a tunnelcoupling to load the atoms into the same optical tweezer but in distinct motional states. By initially preparing the atoms in opposing spinstates, contact interactions between the atoms, along with their quantum statistics, yield entangling spinswapping dynamics. We experimentally verify that upon separating the atoms subsequent to these dynamics, the entanglement achieved prior is retained. We will also present our recent realization of deterministic loading of 87Rb atoms into an optical tweezer via the techniques developed in Ref. [2]; we achieve fast loading with up to 91{\%} probability. In combination, these techniques demonstrate a novel platform using mobile optical tweezers for loading uniform atom arrays for quantuminformation applications. \\[4pt] [1] Kaufman et al., Twoparticle quantum interference in tunnelcoupled optical tweezers, Science \textbf{345}, 306309 (2014)\\[0pt] [2] Gr\"{u}nzweig et al., Neardeterministic preparation of a single atom in an optical microtrap, Nature Phy. \textbf{6}, 951954 (2010) [Preview Abstract] 

Q1.00174: Analytical application of femtosecond laserinduced breakdown spectroscopy Noureddine Melikechi, Yuri Markushin We report on significant advantages provided by femtosecond laserinduced breakdown spectroscopy (LIBS) for analytical applications in fields as diverse as protein characterization and material science. We compare the results of a femto and nanosecondlaserinduced breakdown spectroscopy analysis of dualelemental pellets in terms of the shottoshot variations of the neutral/ionic emission line intensities. This study is complemented by a numerical model based on twodimensional random close packing of disks in an enclosed geometry. In addition, we show that LIBS can be used to obtain quantitative identification of the hydrogen composition of biomacromolecules in a heavy water solution. Finally, we show that simultaneous multielemental particle assay analysis combined with LIBS can significantly improve macromolecule detectability up to near single molecule per particle efficiency. [Preview Abstract] 

Q1.00175: Dynamics of Two Overlapping Spin Ensembles Interacting by Spin Exchange with Large Rb Magnetization Field Yao Chen, Jiancheng Fang Two spin ensembles which occupy the same volume in a spherical alkali vapor cell can coupled together by the spin exchange interaction. In a KRb$^{21}$Ne comagnetometer which was used for rotation sensing, Rb atomic spins and the $^{21}$Ne nuclear spins couple together by spin exchange. Due to the large Rb density and the Fermi contact constant of Rb$^{21}$Ne pair, the magnetization field of Rb atomic spins is much larger than that of the K in a K$^{3}$He comagnetometer. At the comagnetometer working point, the precession frequency of Rb atomic spins are much larger than that of the $^{21}$Ne spins. The decay rate and precession frequency of $^{21}$Ne atoms is much smaller than that of the point when the precession frequencies of the Rb and $^{21}$Ne atoms are the same. In this experiment, the dynamics of the Rb $^{21}$Ne pair at different holding magnetic field point were studied. The frequency response of the comagnetometer to oscillating magnetic field at different holding magnetic field point was also studied. [Preview Abstract] 

Q1.00176: Results of a direct search for the thorium229 nuclear isomeric transition Christian Schneider, Justin Jeet, Scott T. Sullivan, Wade G. Rellergert, Saed Mirzadeh, A. Cassanho, H.P. Jenssen, Eugene V. Tkalya, Eric R. Hudson The nucleus of thorium229 has an exceptionally lowenergy isomeric transition in the vacuumultraviolet spectrum around $7.8 \pm 0.5$eV [1]. The prospects of a laseraccessible nuclear transition are manifold but require spectroscopically resolving the transition. Our approach is a direct search using thoriumdoped crystals as samples and exciting the isomeric state with vacuumultraviolet synchrotron radiation [2]. In a recent experiment, we were able to search for the transition at the Advanced Light Source synchrotron, LBNL, between $7.3$eV and $8.8$eV. We found no evidence for the transition within a lifetime range of 12s to 20005600s [3]. This result excludes large parts of the theoretically expected region. We conclude reporting on our efforts of a search using lasergenerated vacuumultraviolet light. \\[4pt] [1] B. R. Beck et al.: LLNLPROC415170 (2009)\\[0pt] [2] W. G. Rellergert et al.: Phys. Rev. Lett. 104, 200802 (2010)\\[0pt] [3] J. Jeet et al.: arXiv 1502.02189 (2015) [Preview Abstract] 

Q1.00177: Vectorial atomic magnetometer using electronic and nuclear Binquan Zhou, Linlin Chen, Guanqun Lei, Xiaofeng Meng, Jiancheng Fang We present an experimental study of a vectorial atomic magnetometer, which can measure threedimensional magnetic field simultaneously. The experimental setup for magnetometer has been described in the literature [1]. Where an external magnetic field is added parallel to the pumping light, that the goal is to switch the nuclear spin state form an undesired state to the desired state creating a gas whose atoms are completely aligned. A probe light is added perpendicular to the pumping light. When there is transverse alternating magnetic field, the probe light will be modulated by the spin procession. We obtain the two transverse magnetic fields signal through the inphase and outofphase of a lockin amplifier, At the same time, the external magnetic field held constant relative to the external frequency reference, two nuclear signals can be used to measure z vertical magnetic field by comparing the measured two nuclear signal to a second stable reference signal generated by the same external frequency. Once the output signal is feedbacked to the coil, the external threedimensional magnetic field is measured in realtime. The dynamic range can be adjusted through the external magnetic field,so this method can be used both in the magnetic surveys and in the prospecting field range.\\[4pt] [1] Orang Alem and Karen L. Sauer and M. V. Romalis. Phys. Rev. A 87, 013413 (2013). [Preview Abstract] 
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