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 K1: Poster Session II (4:00 pm  6:00 pm) 
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Room: Convention Center Battelle South 

K1.00001: LASER COOLING AND TRAPPING 

K1.00002: Nondestructive Phase Shifting Imaging of Cold Atoms ChihChieh Lin, YingHsian Wang, HungShiue Chen, PoJui Tseng, Z.X. Fan, DianJiun Han We propose a nondestructive phase shifting imaging for cold atoms by using a Gaussian beam and accompanying with phase shifting interferometry in a MachZehnder interferometer [12]. This imaging scheme could require no imaging lens. Hence, aberration associated with it is completely eliminated and mechanical focusing can be avoided. Compared to the common singlebeam nondestructive means [3], our proposed scheme allows energy per probe pulse delivered to the cold samples lowered by almost three orders of magnitude due to signal enhancement inherently provided in the twobeam configuration. In this meeting, we will describe the working principle and show our experimental realization of this novel nondestructive detection means for insitu imaging on the rubidium87 atoms confined in a magnetooptical trap. Besides, we will present measured data to demonstrate the focusing capability provided in this scheme as well, though no imaging lens is used.\\[4pt] [1] TzuPing Ku\textit{ et al}., Opt. Express \textbf{19}, 3730 (2011).\\[0pt] [2] ChihYuan Huang \textit{et al}., J. Opt. Soc. Am. B \textbf{31}, 87 (2014).\\[0pt] [3] M. R. Andrews \textit{et al}., Science \textbf{273}, 84 (1996). [Preview Abstract] 

K1.00003: A lowcost, tunable laser lock without laser frequency modulation Margaret E. Shea, Paul M. Baker, Daniel J. Gauthier Many experiments in optical physics require laser frequency stabilization. This can be achieved by locking to an atomic reference using saturated absorption spectroscopy. Often, the laser frequency is modulated and phase sensitive detection used. This method, while wellproven and robust, relies on expensive components, can introduce an undesirable frequency modulation into the laser, and is not easily frequency tuned. Here, we report a simple locking scheme similar to those implemented previously.\footnote{TP Dinneen, CD Wallace, and PL Gould, {\em Opt. Comm.} \textbf{92}, 277 (1992)}\textsuperscript{,}\footnote{S Pradhan, R Behera, and AK Das, {\em Pramana  J. Phys.} \textbf{78}, 4 (2012)} We modulate the atomic resonances in a saturated absorption setup with an AC magnetic field created by a single solenoid. The same coil applies a DC field that allows tuning of the lock point. We use an autobalanced detector\footnote{PCD Hobbs, {\em Appl. Opt.} \textbf{36}, 903920 (1997)} to make our scheme more robust against laser power fluctuations and stray magnetic fields. The coil, its driver, and the detector are homebuilt with simple, cheap components. Our technique is lowcost, simple to setup, tunable, introduces no laser frequency modulation, and only requires one laser. [Preview Abstract] 

K1.00004: Measurements of the Velocity Dependence of the ARP Force John Elgin, He Zhang, H. Metcalf Adiabatic Rapid Passage (ARP) has previously been shown to produce optical forces that are much larger than the radiative force on atoms at or near rest.\footnote{X. Miao, Phys. Rev. A 75, 011402 (2007)} However, in order for a force to be useful for laser cooling, it needs to be velocity dependent over a finite region. Our experimental setup uses light from two externallymodulated diode lasers with variable detunings, and is designed to measure this velocity dependence. Our initial results show some unexpected features, mainly that the force {\it vs.} velocity profile displays narrow resonances at certain velocities, corresponding to both fractions and multiples of the lasers' modulation frequency. Numerically solving the Optical Bloch Equations for the experimental ARP conditions provides insight into these features. We present both experimental and numerical results, and interpret their implications for the usefulness of ARP in laser cooling applications. [Preview Abstract] 

K1.00005: Toward a cold hybridtrap measurement of chargeexchange between Na and Ca$^+$: Na excited state fraction James E. Wells, Douglas S. Goodman, Jonathan M. Kwolek, Reinhold Blumel, Frank A. Narducci, Winthrop W. Smith We present progress towards the measurement of the chargeexchange collision rate coefficient between neutral sodium and ionic calcium. The rate constant for charge exchange between ground state sodium and calcium ion has been previously calculated and predicts a lifetime in our system of the order of days.\footnote{O.P. Makarov, et al. PRA 67, 042705 (2003).} Experiments by our group show a much larger charge exchange collision rate, probably from the excited 3P state of sodium.\footnote{W.W. Smith, et al., Applied Phys. B 114, 75 (2014).} Therefore, an accurate measurement of the charge exchange collision rate constant will require an accurate value for the excited state fraction of the Na MOT. We have developed a technique for making a modelindependent measurement of the excited state fraction of a MOT inside a hybrid trap. We compare the measured excited state fraction using this technique with measurements assuming a twolevel model of the atom. In addition, we review our recent measurement of the total elastic and resonant charge exchange collision rate between Na and Na$^+$.\footnote{D.S. Goodman, et al PRA 91, 012709 (2015).} [Preview Abstract] 

K1.00006: Towards Laser Cooling Trapped Ions with Telecom Light Kristina Dungan, Patrick Becker, Liz Donoghue, Jackie Liu, Steven Olmschenk Quantum information has many potential applications in communication, atomic clocks, and the precision measurement of fundamental constants. Trapped ions are excellent candidates for applications in quantum information because of their isolation from external perturbations, and the precise control afforded by laser cooling and manipulation of the quantum state. For many applications in quantum communication, it would be advantageous to interface ions with telecom light. We present progress towards laser cooling and trapping of doublyionized lanthanum, which should require only infrared, telecomcompatible light. Additionally, we present progress on optimization of a secondharmonic generation cavity for laser cooling and trapping barium ions, for future sympathetic cooling experiments. [Preview Abstract] 

K1.00007: All optical production of a large BEC of $^{87}$Rb in two compressible crossed dipole force traps Kazuya Yamashita, Kouhei Hanasaki, Akihiro Ando, Hiroshi Kanemitsu, Ryosuke Goto, Toshiya Kinoshita We describe our all optical method to make BEC of $^{87}$Rb. By adiabatically releasing a dense cold atomic gas from 3D FORLs, 2x10$^7$ atoms are loaded into different two crossed dipole force traps (CDTs), created by 8W multimode fiber laser and 1.6W single mode fiber laser, respectively. Both CDTs are simultaneously compressed, but the trap size of the single mode laser is much smaller than the other. After the compression, first we decrease only the multimode laser power gradually and shut it off. The evaporation is continued in the tight CDT by the single mode laser. An almost pure BEC of 1x10$^6$ atoms is created in totally $\sim$ 3.3 s evaporations. We could minimize heating due to Raman process which is often pointed out when using high power multimode fiber lasers. [Preview Abstract] 

K1.00008: Mechanical and electronic energy eigenstates of neutral Rb atoms in deep optical lattices Andreas Neuzner, Matthias Koerber, Olivier Morin, Stephan Ritter, Gerhard Rempe Optical lattices allow for tight threedimensional confinement of neutral atoms in quasiharmonic potentials and have become a standard tool in experimental quantum optics. Applications range from fundamental topics like metrology to applications in quantum communication and quantum information processing. Here we present an experimental characterization of the motional and internal energy eigenstates of optically trapped $^{87}$Rb atoms. We implement different spectroscopy techniques based on nondestructive hyperfine state detection using an optical cavity. Applying these techniques, we observe and explain a series of effects like the decoupling of the hyperfine spin due to a tensor lightshift and mechanical effects associated with a small nonorthogonality of the lattice axes. Furthermore, we succeed to exploit the latter for optical cooling of a single atom into the twodimensional mechanical groundstate in an environment with restricted optical access. [Preview Abstract] 

K1.00009: Laser Cooling Without Spontaneous Emission Using the Bichromatic Force Christopher Corder, Brian Arnold, Xiang Hua, Harold Metcalf We have demonstrated laser cooling without spontaneous emission using the bichromatic force (BF).\footnote{C. Corder et al., Phys. Rev. Lett. \textbf{114}, 043002 (2015).}$^,$\footnote{C. Corder et al., J. Opt. Soc. Am. B, submitted.} It works by restricting the atomlight interaction to a time short compared to a cycle of absorption followed by spontaneous emission. The BF exploits multiple absorptionstimulated emission cycles to cause many rapid momentum exchanges, with these cycles redistributing both energy and entropy between the atoms and light fields in the total atoms+light system. This momentum exchange is restricted to a welldefined velocity range, resulting from nonadiabatic transitions at a velocity that can be understood from simple energy conservation. The observed width of our onedimensional velocity distribution is reduced by $\times$2 thereby reducing the ``temperature'' by $\times$4. Moreover, our results comprise a compression in phase space because the spatial expansion of the atomic sample is negligible. We have also done various simulations of the motion of atoms under the BF and they compare well with our data. This accomplishment is of interest to direct laser cooling of molecules or in experiments where working space or time is limited. [Preview Abstract] 

K1.00010: Progress toward $^{174}$Yb BEC realization for Quantum Simulation Jongchul Mun, Jeongwon Lee, Jae Hoon Lee, Jiho Noh We report the progress in building our experimental setup for $^{174}$Yb BEC. The experimental setup consists of the conventional Zeeman slower and new type of magnetooptical trap(MOT), which we propose and demonstrate for alkalineearthmetallike atoms. This new type of MOT, which we call coreshell MOT, utilizes both the broad $^1\mathrm{S}_0 \rightarrow {}^1\mathrm{P}_1$ transition and the narrow $^1\mathrm{S}_0 \rightarrow {}^3\mathrm{P}_1$ transition in two spatialy seperated regions. Experimental implementation of this scheme showed both faster loading and high atom numbers, by more than two orders and one order of magnitude respectively, compared to conventional MOT schemes. We plan to further cool and transfer the atomic sample into a science chamber by displacing an optical dipole trap using an optically compensated zoomlens. The atoms will be loaded into an optical lattice for quantum simulations. [Preview Abstract] 

K1.00011: Simulating narrow nonlinear resonance features for magnetometry in compact cold atom systems David Meyer, Jenn Robinson, Paul Kunz, Qudsia Quraishi We are investigating cold atom magnetometry applications and have developed a numeric model of Electromagnetically Induced Absorption (EIA) and Nonlinear MagnetoOptical Rotation (NMOR) for degenerate twolevel systems. While most EIA and NMOR research is done in warm vapors, cold atoms avoid Doppler broadening and better isolate the various optical pumping mechanisms involved. Our model focuses on the effect of transverse magnetic fields on both EIA and NMOR features and shows that critical points of both yield quantitative measures of the magnitude and direction of the transverse field. This dependence reveals the underlying optical pumping mechanisms and makes possible a single, insitu measurement of the background magnetic field zero to the submilligauss level, reducing background fields to enhance subDoppler cooling and collectivelyenhanced neutralatom quantum memory lifetimes. Separately, we are pursuing experimental measurements on the relationship between EIA and NMOR in a compact cold atom apparatus. To improve the system's capabilities we are designing our nextgeneration atom chip to reduce system size and employ versatile geometries enabling multisite trapping. [Preview Abstract] 

K1.00012: The Optical Bichromatic Force in Molecular Systems Leland Aldridge, Scott Galica, E.E. Eyler The optical bichromatic force has been demonstrated to be useful for slowing atomic beams much more rapidly than radiative forces. Through numerical simulations, we examine several aspects of applying the bichromatic force to molecular beams. One is the unavoidable existence of outofsystem radiative decay, requiring one or more repumping beams. We find that the average deceleration varies strongly with the repumping intensity, but when using optimal parameters, the force approaches the limiting value allowed by population statistics. Another consideration is the effect of fine and hyperfine structure. We examine a simplified multlevel model based on the $B\leftrightarrow X$ transition in calcium monofluoride. To circumvent optical pumping into coherent dark states, we include two possible schemes: (1) a skewed dc magnetic field, and (2) rapid optical polarization switching. Our results indicate that the bichromatic force remains a viable option for creating large forces in molecular beams, with a reduction in the peak force by approximately an order of magnitude compared to a twolevel atom, but little effect on the velocity range over which the force is effective. We also describe our progress towards experimental tests of the bichromatic force on a molecular beam of CaF. [Preview Abstract] 

K1.00013: AC Zeeman potentials for atom chipbased ultracold atoms Charles Fancher, Andrew Pyle, Austin Ziltz, Seth Aubin We present experimental and theoretical progress on using the AC Zeeman force produced by microwave magnetic nearfields from an atom chip to manipulate and eventually trap ultracold atoms. These AC Zeeman potentials are inherently spindependent and can be used to apply qualitatively different potentials to different spin states simultaneously. Furthermore, AC Zeeman traps are compatible with the large DC magnetic fields necessary for accessing Feshbach resonances. Applications include spindependent trapped atom interferometry and experiments in 1D manybody physics. Initial experiments and results are geared towards observing the bipolar detuningdependent nature of the AC Zeeman force at 6.8 GHz with ultracold $^{87}$Rb atoms trapped in the vicinity of an atom chip. Experimental work is also underway towards working with potassium isotopes at frequencies of 1 GHz and below. Theoretical work is focused on atom chip designs for AC Zeeman traps produced by magnetic nearfields, while also incorporating the effect of the related electric nearfields. Electromagnetic simulations of atom chip circuits are used for mapping microwave propagation in onchip transmission line structures, accounting for the skin effect, and guiding impedance matching. [Preview Abstract] 

K1.00014: New Approaches for Producing Quantum Degenerate Gases of Strontium Roger Ding, Germano Woehl Jr., Francisco Camargo, Joseph Whalen, F. Barry Dunning, Thomas Killian We investigate two novel methods for laser cooling strontium to quantum degeneracy. The first takes advantage of the isotope shifts and the narrow $^1S_0$$^3P_1$ intercombination line (7.5 kHz at 689 nm) to produce an isotope selective optical dipole trap (ODT). We demonstrate this technique by sympathetically cooling $^{88}$Sr or $^{87}$Sr using $^{86}$Sr to produce quantum degenerate gases. The second uses an acoustooptic modulator driven with multiple RF frequencies to dynamically shape a faroff resonance ODT. This is easy to implement in existing traps and allows for optimized loading and evaporation tailored for each isotope. The simple setup has been applied in various atomic physics experiments [1, 2], and we describe its application in strontium. \\[4pt] [1] D. Trypogeorgos, T. Harte, A. Bonnin, and C. Foot, ``Precise shaping of laser light by an acoustooptic deflector,'' Opt. Express 21, 2483724846 (2013).\newline [2] K. Roberts, T. McKellar, J. Fekete, A. Rakonjac, A. Deb, and N. Kj\ae rgaard, ``Steerable optical tweezers for ultracold atom studies,'' Opt. Lett. 39, 20122015 (2014). [Preview Abstract] 

K1.00015: Arduinobased laboratory instruments for an undergraduate laser cooling experiment Timothy Ireland, Gage Tiber, Robert W.A. Brooke, Julie M. Gillis, Christopher A. Zaccagnini, Theodore A. Corcovilos Arduino is an inexpensive opensource microcontroller platform designed for quick development turnaround and easy interfacing, making it ideal for novice programmers and instrument designers. Based on Atmel ATMEGA microcontroller chips, the Arduino boards are programmed with standard C/C++ code and contain sufficient inputs and outputs (both digital and analog) for basic data acquisition and device control. Here we present homebuilt Arduinobased instruments commonly used in lasercooling experiments, such as a wavelength meter and temperature controller. We describe the design and performance of these instruments. [Preview Abstract] 

K1.00016: Laser cooling and trapping with optical frequency combs Xueping Long, Andrew Jayich, Anthony Ransford, Anna Wang, Wesley Campbell A large number of atoms and molecules are difficult to control with continuous wave lasers because generating sufficient power at all of the necessary wavelengths is technologically challenging. Modelocked lasers, through their enhanced efficiency of nonlinear frequency conversion, provide some of these hard to access wavelengths. As a step towards control of exotic atoms and molecules we report on laser cooling and trapping of atoms using an optical frequency comb in two different regimes. Using a single comb, we have created a simultaneous dualspecies (isotopes) MOT, demonstrating that multiple comb teeth can be used in parallel~to cool and confine species requiring many cw lasers. Separately, we demonstrate combbased laser cooling on a twophoton transition, which efficiently uses the full timeaveraged optical power of the entire comb [1]. Our progress toward~extending this to include trapping by making a MOT using this twophoton transition is presented. This work is supported by the National Science Foundation \\[4pt] [1] D. Kielpinski, Phys. Rev. A 73, 063407 (2006) [Preview Abstract] 

K1.00017: Fast Acting Optical Forces From Far Detuned, High Intensity Light Christopher Corder, Brian Arnold, Xiang Hua, Harold Metcalf We are exploring fast acting, strong optical forces from standing wave light fields with high intensity and large detuning $\delta\gg\gamma$, where $\gamma$ is the transition linewidth. We observe these fast acting forces on a time scale of a few times the excited state lifetime $\tau\equiv 1/\gamma$; thus an atom may experience at most one or two spontaneous emission events. The dipole force is typically considered when the Rabi frequency $\Omega\ll\delta$, but we use $\Omega\sim\delta$ so the usual approximations break down because a significant excited state population can occur, even for our short interaction times that limit spontaneous emission. Our experiment measures the transverse velocity distribution of a beam of 2$^3$S He after a chosen interaction time with a perpendicular standing wave detuned from the 2$^3$S$\rightarrow$3$^3$P transition near 389 nm. The distribution shows velocity resonance effects that persist over a large range of $\Omega$. We also simulate the experiment numerically using the Optical Bloch Equations and the results are consistent with our measurements. [Preview Abstract] 

K1.00018: Trapping and dynamics of levitated ice particles at low pressures Nicholas Kowalski, Bernard Xie, Colin Parker, Cheng Chin We report on experimental methods for trapping ice particles in medium vacuum, at pressures between 5 Torr and 25 Torr. At appropriate conditions aggregate ice particles hover at short distances due to the Knudson compressor effect. Additionally particles can launch and levitate robustly for extended periods of time. First we describe the experimental setup used to produce levitation, including producing the temperature gradients across the chamber. Additionally we describe our procedure for generating and introducing ice into the experimental setup. We describe the conditions necessary for levitation, and the dependence of levitation on the experimental parameters. In addition, we report on the behavior of particles during levitation and ejection, including position and stability, by analyzing particle trajectories. This includes events in which simultaneously levitated particles collide and merge. [Preview Abstract] 

K1.00019: Enhanced Magnetic Trap Loading and Coupled Optical Resonance Spectroscopy in Strontium Daniel S. Barker, Benjamin J. Reschovsky, Neal C. Pisenti, Gretchen K. Campbell We investigate a technique to improve the loading of atomic strontium into a magnetic trap using a 688 nm depump laser on the $^3$P$_1$  $^3$S$_1$ transition. Strontium degenerate gas experiments typically use a magnetic trap continuously loaded from a MagnetoOptical Trap (MOT) operating on the 461 nm line. A slow ($\approx$1:50,000) leak from the MOT transition populates the magnetically trapped $^3$P$_2$ state and the $^3$P$_1$ state in a 1:2 ratio. Pumping $^3$P$_1$ atoms into $^3$P$_2$ accelerates magnetic trap loading. For this purpose, we stabilize a 688 nm laser using Coupled Optical Resonance Laser Locking (COReLL [1]) to the 679 nm, 688 nm, and 707 nm lines. The technique allows us to lock multiple lasers while only detecting absorption on the 707 nm transition. Error signals are generated with incommensurate frequency modulation of the pump beams. Preliminary application of the 688 nm laser to our $^{88}$Sr MOT results in 20\% enhancement of magnetic trap atom number. We discuss the limitations of the loading rate enhancement and the potential for loading enhancement with other repumping strategies.\\[4pt] [1] S C Burd, P J W du Toit, and H Uys. Coupled optical resonance laser locking. \textit{Optics express}, 22(21):740743, 2014. [Preview Abstract] 

K1.00020: Compact, Onchip, Integrated three dimensional Lattice Phoebe M. Tengdin, Evan A. Salim, Dana Z. Anderson We present the design of a compact atom chip system that provides a three dimensional optical lattice combined with thruchip imaging. Optical beams are launched from fibers mounted directly to the exterior of a high resolution (0.4NA) imaging objective. Miniature polarizers, wave plates, and mirrors located on the exterior of the objective control the polarization state and alignment of the lattice, while onchip optics are used to provide retroreflection. Three mutually orthogonal lattice beams traverse from the ambient side of the chip through a central window of a silicon and glass substrate, intersecting 300 microns below the vacuum side chip surface. The combined atom chip and optical system fills a volume of less than 36 cm$^{3}$. Atoms may be cooled using standard techniques [1], and directly loaded into the optical lattice. This system is designed with the intention of reducing vibrational noise, providing high resolution inlattice imaging, combining electric and magnetic fields to generate arbitrary potentials, and performing high repetition rate experiments. \\[4pt] [1] Farkas, Daniel M. et al. Appl. Phys. Lett, 96, 093102 (2010). [Preview Abstract] 

K1.00021: Laser cooling of nuclear spin 0 alkali $^{78}$Rb J.A. Behr, A. Gorelov, M. Anholm The textbook example for subDoppler cooling is a J=1/2 I=0 alkali atom in lin $\perp$ lin molasses. In the $\sigma^+$ $\sigma^$ configuration of a standard MOT, the main subDoppler cooling mechanism relies on changing alignment ($M_F^2$ population) with the summed linear polarization orientation, but there is no such variation in AC Stark shift for F=1/2. We have nevertheless looked for signs of subDoppler cooling by trapping I=0 $^{78}$Rb in a standard MOT and measuring the cloud size as a function of laser detuning and intensity. The $^{78}$Rb cloud size does not change significantly with lowered intensity, and expands slightly with detuning, consistent with minimal to no subDoppler cooling. Our geometry does show the wellknown substantially smaller cloud size with detuning and intensity for I=3/2 $^{87}$Rb. Maintaining an I=0 alkali cloud size with lowered intensity will help our planned $\beta$$\nu$ correlation experiments in $^{38m}$K decay by suppressing possible production of photoassisted dimers. [Preview Abstract] 

K1.00022: Loading an Rb87 MOT directly into a variableperiod accordion lattice John Huckans We report on our progress toward loading an Rb87 threedimensional magnetooptical trap (3D MOT) directly into a twodimensional variableperiod optical lattice\footnote{J.H. Huckans, Univ. of Maryland doctoral dissertation (2006).}$^,$\footnote{L. Fallani \textit{et al}., Opt. Express \textbf{13}, 43034313 (2005).} (2D accordion lattice). Preliminary calculations suggest the feasibility of achieving an approximate 10$^{2}$ increase in phase space density by combining graymolassestype cooling techniques\footnote{G. Salomon~\textit{et al}., \textit{EPL}~\textbf{104,}~63002 (2013).} with spatial density compression of a 3D MOT with an accordion lattice. [Preview Abstract] 

K1.00023: Radiation Force induced Liquid Flow within a Homogeneous Medium Honggu Choi, Boram Joo, Jeong Jisung, Kyunghwan Oh The visualization of optical force required refractive index inhomogeneous boundary, or absorption to generate radiation pressure. However, the dilute liquid medium with low attenuation coefficient is affected by light carrying momentum, and generated flow. The optical force density within a dielectric medium oscillates, and their time averaged value was regarded as a vanishing parameter, however the existence of light carrying momentum within a dielectric media generates material momentum density and it results localized liquid flow. We used 980nm fiber laser source guided along HI1060 single mode fiber which guides localized single mode Poynting vector, in order to generate effectively measureable radiation pressure during light propagation within deionized water. The micro beads with 2 micrometer diameter were deployed to visualize the flow and their location was out of beam to reject the effect of radiation pressure at the refractive index inhomogeneity between water and polymer beads. [Preview Abstract] 

K1.00024: Localfield corrections in a Dopplerbroadened gas Yi Li, Juha Javanainen We introduce the thermal motion of atoms into our classicalelectrodynamics simulations to study the cooperative response of a nearresonant gas to light. The simulation results for the shift of the resonance line are closer to the standard prediction from localfield corrections plus ``cooperative Lamb shift'' than we have seen either in dilute homogeneously broadened atomic samples or in cases when inhomogeneous broadening is modeled with a random distribution of resonance frequencies of stationary atoms. Inhomogeneous broadening due to the motion of the atoms may be a key factor in establishing the traditional phenomenology of localfield corrections. [Preview Abstract] 

K1.00025: QUANTUM PHASES AND ATOMS IN OPTICAL LATTICES 

K1.00026: Floquet Edge States with Ultracold Atoms Matthew Reichl, Erich Mueller We describe an experimental setup for imaging topologically protected Floquet edge states using ultracold bosons in an optical lattice. Our setup involves a deep twodimensional optical lattice with a timedependent superlattice that modulates the hopping between neighboring sites. The finite waist of the superlattice beam yields regions with different topological numbers. One can observe chiral edge states by imaging the realspace density of a bosonic packet launched from the boundary between two topologically distinct regions. [Preview Abstract] 

K1.00027: Equilibrium phases of twodimensional bosons in quasiperiodic lattices Chao Zhang, Arghavan SafaviNaini, Barbara CapogrossoSansone We report on results of Quantum Monte Carlo simulations for bosons in a two dimensional quasiperiodic optical lattice. We study the ground state phase diagram at unity filling and confirm the existence of three phases: superfluid, Mott insulator, and Bose glass. At lower interaction strength, we find that sizable disorder strength is needed in order to destroy superfluidity in favor of the Bose glass. On the other hand, at large enough interaction, superfluidity is completely destroyed in favor of the Mott insulator (at lower disorder strength) or the Bose glass (at larger disorder strength). At intermediate interactions, the system undergoes an insulator to superfluid transition upon increasing the disorder, while a further increase of disorder strength drives the superfluid to Bose glass phase transition. [Preview Abstract] 

K1.00028: Phase diagram of porbital attractive fermions in a twodimensional optical lattice Theja De Silva We study multiorbital system of polarized fermions on a twodimensional square lattice with attractive onsite interaction. We assume that the atoms are loaded to the lattice such that the $s$orbital is completely filled and dynamic of the system is determined by the $p$orbital atoms. By including the foursite square plaquette interaction term generated from the directional tunneling dependence at half filling, we derive an effective spinHamiltonian using forth order perturbation theory at the strongly interacting limit. We then use a variational mean field approach to map out the phase diagram. [Preview Abstract] 

K1.00029: Double occupancies and compressibility in a disordered Mott insulator Philip Russ, Carolyn Meldgin, Brian DeMarco A complete picture describing the interplay between disorder and interactions remains elusive. We explore this problem in the regime of strong interactions using an ultracold atomic Bose gas in a 3dimensional disordered optical lattice. Starting with a unitfilling Mott insulator, we measure how disorder changes the fraction of doubly occupied sites. By measuring how the fraction of double occupancies changes when the atom number is varied near unitfilling, we extract the compressibility of the system. We compare the onset of finite compressibility to theoretical predictions for the disorderinduced emergence of a compressible Bose glass. [Preview Abstract] 

K1.00030: Rotonmaxon excitation spectrum of Bose condensates in a shaken optical lattice LiChung Ha, Logan W. Clark, Colin V. Parker, ChenYu Xu, Cheng Chin We present a resonant lattice shaking technique for engineering the dispersion of a cesium Bose condensate. Through phase modulating an optical lattice at a frequency near the band splitting, the dispersion of the condensate can evolve from quadratic to quartic and finally into a doublewell structure. We observe effective ferromagnetism in the doublewell regime [1], and atoms form domains within one well in momentum space. We study the elementary excitations of this system by implementing projectionbased Bragg spectroscopy and find a rotonmaxon feature in the excitation spectrum in agreement with a Bogoliubov calculation [2]. Consistent with Landau's prediction, we observe a suppressed superfluid critical velocity due to the existence of the roton. We will introduce more precise characterizations of the dispersion in an effort to pinpoint the critical point at which the dispersion is purely quartic, and study the dynamics of particles in that case. This work is supported by NSF, ARO and Chicago MRSEC. \\[4pt] [1] Direct observation of effective ferromagnetic domains of cold atoms in a shaken optical lattice, Nature Physics 9, 769 (2013).\\[0pt] [2] Rotonmaxon excitation spectrum of Bose condensates in a shaken optical lattice, Phys. Rev. Lett. (in press). [Preview Abstract] 

K1.00031: A novel experiment for coupling a BoseEinstein condensate with two crossed cavity modes Julian Leonard, Andrea Morales, Philip Zupancic, Tobias Donner, Tilman Esslinger Over the last decade, combining cavity quantum electrodynamics and quantum gases made it possible to explore the coupling of quantized light fields to coherent matter waves, leading e.g. to new optomechanical phenomena and the realization of quantum phase transitions. Triggered by the interest to study setups with more complex cavity geometries, we built a novel, highly flexible experimental system for coupling a BoseEinstein condensate (BEC) with optical cavities, which allows to switch the cavity setups by means of an interchangeable science platform. report on our latest results on coupling a BoseEinstein condensate with two crossed cavity modes intersecting under an angle of 60$^{\circ}$. The mirrors have been machined in a way to spatially approach them, thus obtaining maximum single atom coupling rates of several MHz. This setup will allow the study of selfordered phases in different lattice shapes, such as hexagonal and triangular geometries. [Preview Abstract] 

K1.00032: Competing Orders in a Dipolar Bose  Fermi Mixture on a Square Optical Lattice: MeanField Perspective Hong Ling, Jasen Scaramaazza, Ben Kain We study superfluid pairings of twocomponent fermions interacting by exchanging virtual phonons of a dipolar condensate in an optical lattice that preserves the symmetry of D4. We construct, within the HartreeFockBogoliubov theory, the matrix representation of the linearized gap equation in the irreducible representations of D4. We find that each matrix element, which is a fourdimensional (4D) integral in momentum space, can be put in a separable form involving a 1D integral, which is only a function of temperature and the chemical potential, and a pairingspecific ``effective'' interaction, which is an analytical function of the parameters that characterize FermiFermi interactions. We analyze the critical temperatures of various competing orders (superfluids with s, d$_{x^2y^2}$, d$_{xy}$, and gwave symmetries and density waves) as functions of different system parameters in both the absence and presence of the dipolar interaction. We find that tuning a dipolar interaction can dramatically enhance various unconventional pairings. [Preview Abstract] 

K1.00033: Towards quantum simulation of the Hubbard model with attractively interacting fermions Debayan Mitra, Peter Brown, Mark Stone, Stanimir Kondov, Waseem Bakr Ultracold atoms in optical lattices have emerged as a versatile platform for quantum simulations of condensed matter models. The singleband, twodimensional repulsive Hubbard model is a simple model of electrons tunneling in a lattice with onsite interactions. The model may potentially capture the essential physics of the high critical temperature cuprate superconductors. Although some general features of the phase diagram of the model are known, quantitative predictions are notoriously difficult and many open questions remain, including whether it even supports dwave superconductivity. We describe progress towards constructing an experiment for performing a quantum simulation of the~attractive~Hubbard model using ultracold Fermi gases in an optical lattice. While previous experiments have focused almost exclusively on the repulsive Hubbard model, there is an exact mathematical mapping between the physics of the repulsive and attractive models. However, it is experimentally established that attractively interacting fermions reach entropies that are an order of magnitude lower than repulsive fermions. Therefore, our experiments with attractive fermions should give access to a much larger part of the phase diagram and allow us to tackle quantitative questions. [Preview Abstract] 

K1.00034: Integrated Atom Chip System for Optical Lattice Experiments Evan A. Salim, Megan K. Ivory, Cameron J.E. Straatsma, Dana Z. Anderson We present an ultracold atom system incorporating a hybrid magnetic/optical atom chip for optical lattice experiments. The atom chip uses integrated, millimeterscale optical elements to enable the production of optical lattice potentials near the atom chip traces and within a few hundred microns of a highquality vacuum window. Due to their proximity to a window, the atoms are addressable by optics outside of vacuum operating at numerical apertures as high as 0.8. Demonstration of BoseEinstein condensation in the chip trap and LandauZener tunneling in a 1D lattice are presented. [Preview Abstract] 

K1.00035: Collisional Microscopy of Quantum Gases Qi Liu, Craig Price, Nathan Gemelke Ultracold atomic gases in optical lattices have emerged as an excellent tool in the study of strongly correlated manybody systems. However the energy and entropy scales often necessary to reveal exotic phenomena require new techniques to probe and new methods to cool quantum gases. We describe a promising technique, collisional microscopy, to image, quantum coherently manipulate, and cool strongly correlated atomic gases. In this microscope, pairwise entanglement is induced between atoms in a sample and an optical lattice of secondary atoms used as probes, and information readout by classical lightscattering from the probes. We detail two collisional entanglement schemes, one via tunnelgate operations, in which the shuffling of probe atoms is conditional on the presence or state of sample atoms, and a second, based on Ramseystyle interferometer sequences in which the collision process is tuned to extract information from the gas under study. Applications of the collision microscope will be discussed, including algorithmic cooling schemes for bosonic Mott insulators, in which localizing information of defects is nondestructively obtained from collisional microscopy and used to adiabatically cool the sample. [Preview Abstract] 

K1.00036: A quantumgas microscope for fermionic potassium Dylan Cotta, James Hudson, Andrew Kelly, Bruno Peaudecerf, Elmar Haller, Stefan Kuhr Recent experiments with singlesite resolution and addressing of strongly correlated rubidium atoms in optical lattices have resulted in the direct observation of, e.g., bosonic Mott insulators, and outofequilibrium physics. Here we present a quantumgas microscope for singleatomresolved fluorescence detection of fermionic $^{40}$K. The atoms are held in a single layer of a 1064\,nm optical lattice and observed by a highresolution optical microscope with numerical aperture NA=0.68. This setup will enable quantum simulation of the FermiHubbard model with singleparticle access, allowing for the direct observation and characterization of, e.g., fermionic Mott insulators, Band insulators, metallic phases or N\'{e}el antiferromagnets. [Preview Abstract] 

K1.00037: A Quantum Gas Microscope for Ultracold Fermions Matthew Nichols, Lawrence Cheuk, Melih Okan, Thomas Lompe, Martin Zwierlein In the past decade ultracold atoms in optical lattices have been established as an ideal model system to study quantum many body physics in a clean and wellcontrolled environment. Recently, experiments at Harvard and MPQ Munich using bosonic $^{\mathrm{87}}$Rb atoms have made these systems even more powerful by demonstrating the ability to observe and address atoms in optical lattices with singlesite resolution. The goal of our experiment is to achieve such singlesite resolution for a quantum gas of fermionic atoms. Such local probing would reveal microscopic density or spin correlations which are difficult to extract from bulk measurements. This technique could for example be used to directly observe antiferromagnetic ordering in a fermionic Mott insulator. As the starting point for our experiments we cool fermionic potassium atoms with bosonic sodium as a sympathetic coolant. The atoms are then loaded into an optical lattice located seven microns below a solid immersion microscope for highresolution imaging. In this poster we describe how we perform singlesite resolved fluorescence imaging of $^{\mathrm{40}}$K atoms in an optical lattice with high detection fidelity. [Preview Abstract] 

K1.00038: LONGRANGE OR ANISOTROPIC INTERACTIONS IN COLD GASES 

K1.00039: Stronglycoupled high$n$ Rydberg atom pairs Shuhei Yoshida, Joachim Burgd\"{o}rfer, Xinyue Zhang, F.B. Dunning Creation of pairs of high $n$, $n \sim 300$, Rydberg atoms with welldefined initial separations enables study and control of their mutual interactions. If the atoms are initially well separated, their interactions are weak and they evolve independently. Their interactions can be dramatically increased, however, by transferring them to even higher levels using carefullytailored sequences of one, or more, short electric field pulses, the degree of coupling being strongly influenced by the final target state. Since both atoms are subject to the same pulse(s), stronglycorrelated macroscopic twoelectron wave packets can be created whose subsequent dynamics can be monitored by application of further probe fields. Interest focuses on energy exchange and formation of long lived twoelectronexcited states in which, due to their correlated motions, the electrons remain far apart. The production and properties of such states, which lie at the classicalquantum interface, are being explored experimentally and through classical and quantum simulations. [Preview Abstract] 

K1.00040: Quantum simulation of magnetic kinks with dipolar lattice gases Lushuai Cao, Xiangguo Yin, Peter Schmelcher We propose an effective Ising spin chain constructed with dipolar quantum gases confined in a onedimensional optical superlattice. Mapping the motional degrees of freedom of a single particle in the lattice onto a pseudospin results in effective transverse and longitudinal magnetic fields. This effective Ising spin chain exhibits a quantum phase transition from a paramagnetic to a singlekink phase as the dipolar interaction increases. Particularly in the singlekink phase, a magnetic kink arises in the effective spin chain and behaves as a quasiparticle in a pinning potential exerted by the longitudinal magnetic field. Being realizable with current experimental techniques, this effective Ising chain presents a unique platform for emulating the quantum phase transition as well as the magnetic kink effects in the Isingspin chain and enriches the toolbox for quantum emulation of spin models by ultracold quantum gases. [Preview Abstract] 

K1.00041: Stability spectroscopy: recurring roton signatures in a dipolarBEC phase diagram John Corson, Ryan Wilson, John Bohn When a stronglydipolar BoseEinstein condensate (BEC) is tightly confined in either one or two dimensions, the excitation spectrum is predicted to exhibit a nontrivial local minimum, termed ``roton.'' Rotons have proven to be elusive in dipolarBEC experiments, and it is therefore of interest to devise a straightforward scheme whereby rotons may be measured. We propose observing the stability of a dipolar BEC that is perturbed by a tunable optical lattice. When the stability is mapped in terms of lattice depth $s$ and spacing $\lambda$, we find regularlyspaced features whose positions and periodicity are determined by the roton wavelength. In this sense, a measurement of the phase diagram represents a spectroscopic measurement of the roton itself. In quasitwodimensional geometry, the polarization tilt plays an important role in determining which features appear in the stability diagram. [Preview Abstract] 

K1.00042: Measurement and simulation of scattering properties of dysprosium Yijun Tang, Nathaniel Burdick, Benjamin Lev, Andrew Sykesy, John Bohn Ultracold collisions can often be characterized by a single parameter, the swave scattering length a, but despite the simplicity of this model, the scattering length a often must be determined experimentally, even for alkali atoms. For highly magnetic lanthanide atoms such as dysprosium (Dy, 10 $\mu_B$), the dipolar interaction may strongly affect the scattering properties and must also be taken into account. We have characterized the elastic crosssection for scattering between ultracold Dy atoms by measuring the rethermalization rate in a Dy clouds driven out of equilibrium. The experimental data agree well with numerical simulations based on Boltzmann equations that include the dipolar interaction contribution. Our recent work on observations of inelastic dipolar scattering will also be briefly discussed [1]. \\[4pt] [1] N. Burdick, K. Baumann, Y. Tang, M. Lu, and B. L. Lev, Phys Rev Lett 114, 023201 (2015). [Preview Abstract] 

K1.00043: SYNTHETIC GUAGE FIELDS AND SPINORBIT COUPLING IN COLD GASES 

K1.00044: Synthetic gauge fields and manybody physics in an optical lattice clock Andrew P. Koller, Michael L. Wall, Shuming Li, Xibo Zhang, Nigel R. Cooper, Jun Ye, Ana Maria Rey We propose the implementation of a synthetic gauge field in a 1D optical lattice clock and explore the resulting singleparticle and manybody physics. The system can realize an effective twoleg ladder by using the two clock states as a synthetic dimension, together with the tunnelingcoupled 1D lattice sites. A large flux per plaquette is naturally generated because the clock laser imprints a phase that varies significantly across lattice sites. We propose to use standard spectroscopic tools  Ramsey and Rabi spectroscopy  to probe the band structure and reveal signatures of the spinorbit coupling, including chiral edge states and the modification of singleparticle physics due to $s$wave and $p$wave interactions. These effects can be probed in spite of the relatively high temperatures ($\sim$ micro Kelvin) and weak interactions, thanks to the exquisite precision and sensitivity of the JILA Sr optical lattice clock. We also discuss the exciting possibility of using the nuclear spin degrees of freedom to realize more exotic synthetic dimension topologies and flux patterns. [Preview Abstract] 

K1.00045: Progress towards a rapidly rotating ultracold Fermi gas MingGuang Hu, Michael Van de Graaff, Eric Cornell, Deborah Jin We are designing an experiment with the goal of creating a rapidly rotating ultracold Fermi gas, which is promising system in which to study quantum Hall physics. We propose to use selective evaporation of a gas that has been initialized with a modest rotation rate to increase the angular momentum per particle in order to reach rapid rotation. We have performed simulations of this evaporation process for a model optical trap potential. Achieving rapid rotation will require a very smooth, very harmonic, and dynamically variable optical trap. We plan to use a setup consisting of two acoustooptical modulators to ``paint'' an optical dipole trapping potential that can be made smooth, radially symmetric, and harmonic. [Preview Abstract] 

K1.00046: Search for Efimov trimers in ultracold atomic mixtures in the presence of spinorbit coupling SuJu Wang, Huili Han, Jesus PerezRios, Chris Greene Realization of synthetic gauge fields in ultracold atomic systems has attracted much attention in both fewbody and manybody physics. Especially, there are extensive works on the twobody aspects of spinorbit coupled quantum gases, which have already shown intriguing new features due to the change in the energy dispersion relation. However, there are few studies on the threebody physics in the presence of spinorbit coupling. In this work, we apply the hyperspherical coordinate approach in the adiabatic approximation to solve the threebody system in zero total angular momentum subspace, where two of them are spinorbit coupled, and the third one of a different species is not. Examination of the computed hyperspherical potential curves should provide the information needed to explore the possible existence of universal threebody bound states. [Preview Abstract] 

K1.00047: Probing microscopic structure and braid statistics in rotating Bose gases Jianshi Zhao, Louis Jacome, Nathan Gemelke It has been predicted that interacting bosonic atoms confined in a rapidly rotating two dimensional harmonic trap exhibit ground states analogous to fractional quantum Hall (FQH) states, and exhibit nonLandauGinzburg order and long range entanglement. Some of these states are expected to have excitations which possess fractional statistics, although no convincing measurement has yet been made. We describe an experiment which seeks to realize FQH physics using cold Rb87 atoms confined to an optical lattice with rotating lattice sites. In these experiments, FQH droplets can be imaged using two highresolution quantum gas microscopes (N.A.=0.4, 0.8) which allow for occupancy resolved measurements, imaging in three dimensions, and expand on previous measurements by providing an unambiguous identification of states through microscopic timeofflight. The latter permits identification of novel properties through counting statistics  using impurity atoms (in a minority spin state), pair correlation measurements can reveal an effectively fractionalized relative angular momentum, indicative of fractionalized braid statistics [1].\\[4pt] [1] Yuhe Zhang, G. J. Sreejith, N. D. Gemelke, and J. K. Jain, PRL 113, 160404 (2014) [Preview Abstract] 

K1.00048: BOSEEINSTEIN CONDENSATES 

K1.00049: A versatile apparatus for the production of degenerate Ytterbium gases Yueyang Zou, Bo Song, ChangWoo Cho, Kwan Hon, Shanchao Zhang, GyuBoong Jo The optical lattice system with ultracold atoms is a promising platform for investigating manybody physics. We describe our ongoing efforts along this line for constructing a versatile ytterbium apparatus designed for the optical detection of atoms with high resolution. The apparatus already allows us to produce a quasipure $^{174}$Yb BoseEinstein condensate of ~40,000 atoms within 12s. Moreover sufficient atomic flux from the 65cm long Zeeman slower would allow us to produce ytterbium BoseFermi mixture in which unprecedented manybody physics can be explored. In this poster, we report on our recent progress and describe our experimental setup. [Preview Abstract] 

K1.00050: Experimental apparatus to study cold collisions in sodium spinor BoseEinstein condensates Delaram Nematollahi, Aaron Foster, Kyle Yates, Joseph Altermatt, Hyoyeon Lee, Qimin Zhang, Arne Schwettmann We present our progress on building an apparatus to study matterwave quantum optics in spin space, including our design of the sodium oven, Zeeman slower, vacuum and laser systems. The nonlinear interaction needed to implement quantum optical devices with matter waves will be provided by spinexchange collisions in a sodium spinor BoseEinstein condensate. Microwave dressing will allow us to exert precise control over the collisional dynamics and tune the system to behave as an interferometer in spin space with reduced noise, or as a phasesensitive amplifier for sensitive atom number measurements. Apart from microwave dressing, we are also planning to study the effect of Rydberg excitations on the collisional spin dynamics of the gas. [Preview Abstract] 

K1.00051: Experimental Progress in a $^6$Li$^{133}$Cs Atomic Mixture Lei Feng, Jacob Johansen, Colin Parker, Cheng Chin We report experimental progress in a mixture of $^6$Li and $^{133}$Cs. The mass imbalance of this system results in a particular challenge, as gravity has a significant influence on Cs position, but not on Li, separating the two gases at temperatures on the order of 200 nK. We overcome this difficulty using a two color optical dipole trap. We demonstrate mixing of these species below 100 nK in preparation for studies of quantum degenerate mixtures of this system. We further report on progress toward degeneracy and manybody physics measurements in this trap. Finally, we consider Efimov physics in this system, studying the effects of CsCs interaction on the spectrum of LiCsCs trimers by a comparison of Feshbach resonances at 843 and 889 G. This work is supported by NSF and Chicago MRSEC. [Preview Abstract] 

K1.00052: Spinor BoseEinstein condensates subject to timedependent microwave dressing: Coherent states vs. Fock states Aaron Foster, Delaram Nematollahi, Arne Schwettmann, Eite Tiesinga We present calculations of the fully quantummechanical spin evolution for a single spatial mode of an F$=$1 antiferromagnetic spinor BoseEinstein condensate in the presence of timedependent microwave dressing. We focus on the coherent spin evolution driven by spinexchange collisions, where two atoms with magnetic quantum number m$=$0 collide and change into a pair with m$=+$/1. We compare and contrast population oscillations for an initial coherent spin (Glauber) state with results for an initial pure number (Fock) state. These simulations are in support of our planned experiments to create and characterize twomode squeezing between the m$=+$/1 spin projections as well as to build a nonlinear interferometer to measure phase with uncertainties that improve upon the shotnoise limit in the number of atoms in the m$=+$/1 states. [Preview Abstract] 

K1.00053: Towards generating synthetic gauge potentials for a BoseEinstein condensate in a toroidal trap Panpan Huang, ChengAn Chen, HungJi Wei, ChinYeh Yu, JungBin Wang, YuJu Lin We have designed a setup to experimentally study ultracold atoms dressed by Raman laser beams in a ringshaped trapping potential. To make BECs of Rb87 atoms, we first capture zeemanslowed atoms in a MagnetoOpticalTrap, perform polarization gradient cooling, and then load the atoms in a quadrupole magnetic trap with a number of $\sim$1e9. After 3.5s of rfevaporation, these precooled atoms are transferred into a hybrid potential, a crossed optical dipole trap with a magnetic gradient. Evaporative cooling of 4.3 s in the dipole trap is performed by first ramping down the power of dipole beams, followed by ramping off the magnetic gradient during which the trap frequency largely remains the same. We achieved a BEC with 2e5 atoms with an experimental cycle time of 15 s. Our next step is to load the atoms into a toroidal dipole trap and use two Raman beams with orbital angular momentum to dress the atoms, thus generating synthetic vector gauge potentials. Both the dipole beam for the toroidal trap and the Raman beam(s) are LaguerreGaussian beams produced by spiral phase plates. [Preview Abstract] 

K1.00054: Rapid Manipulation of BoseEinstein Condensates using Shortcuts to Adiabaticity E. Carlo Samson, Changhyun Ryu, Malcolm Boshier, Adolfo Del Campo We are investigating practical methods based on shortcuts to adiabaticity (STA) for rapid manipulation of BECs. STA is an emergent field in quantum science that develops nonadiabatic protocols to drive a system into a target state much faster than the conventional slow adiabatic process. The first STA method that we are developing involves the ultrafast expansion (or compression) of a trapped BEC, as initially proposed by Del Campo and Boshier [Sci. Rep. 2, 648 (2012)]. We discuss our experimental implementation of this protocol, and our studies of the BEC dynamics and the fidelity of the final state. The other STA method is a launching protocol, in which we accelerate a trapped BEC to a target speed. We show through numerical GPE simulations that the target speed can be achieved in short durations and short launching distances with minimal excitations to the BEC, despite the nonadiabatic nature of the method. We also present initial results from the experimental implementation of this launching protocol. These STAbased experimental techniques would prove beneficial in systems that require fast initial state preparation and cycle time, without loss of coherence nor emergence of perturbations, such as in matter wave circuits, atom interferometry, and quantum heat engines. [Preview Abstract] 

K1.00055: Investigation of quantum chaos using the quantum fidelity in deltakicked rotor Siamak Dadras, Jiating Ni, Wakun Lam, Sandro Wimberger, Gil Summy Several quantum phenomena have been experimentally investigated using the system of ultracold atoms exposed to a spatially and temporally periodic optical potential, the socalled quantum deltakicked rotor. This tool has been widely utilized to study many interesting phenomena such as quantum resonances, dynamical localization, ratchets, and accelerator modes by measuring the atomic momentum distribution. However, the chaotic behavior of quantum systems, in the classical sense of exponentially diverging trajectories in phase space, is still difficult to study merely through the evolution of the momentum distribution. In this respect, we investigate the evolution of the quantum fidelity between two quantum systems experienced slightly different interactions to interpret how the system behaves in deterministic and chaotic phases. We present results of a theoretical study showing how the fidelity between these systems, as well as the correlation between their pseudoclassical phase maps, depend on both the strength and the temporal period of the potential in long term. We also demonstrate the results of corresponding deltakicked rotor experiments with a rubidium87 BoseEinstein condensate confirming our theoretical predictions in finite time. [Preview Abstract] 

K1.00056: Behavior of a new type quantum accelerator mode in phasemodulated optical potential Wakun Lam, Sandro Wimberger, Siamak Dadras, Jiating Ni, Gil Summy It has been shown that the deltakicked rotor (DKR) with a BoseEinstein Condensate is a powerful model for studying the dynamics of manybody systems. Many efforts based on this model have been made in study of dynamical localization, quantum accelerator mode (QAM), to name but a few. QAM is a dynamical phenomenon in which the momentum of atoms exposed to a pulsed accelerating optical standing wave manifest linear growth. In many applications, we expect high transport rate to suppress localization. A recent technique utilizing the phase modulation on the optical potential to produce transport islands [PRE 68, 026209 (2003) and PRA 87, 013631 (2013)] has been discussed. In this presentation we study the stability of such islands in classical phase space of a modified DKR system in which the phase of the optical potential is modulated by a certain phase on each kick. Numerical simulations testify the existence of QAM even in small phase perturbation. We also investigate the momentum distribution numerically and report a new type of QAM which exposed in stationary optical potential instead. The interesting structure of the area of the transport islands against wide range of dynamical parameters is observed to be quite distinct to the regular one. [Preview Abstract] 

K1.00057: Incorporating exact twobody propagators for zerorange interactions into $N$body Monte Carlo simulations Yangqian Yan, D. Blume Ultracold atomic gases are, to a very good approximation, described by pairwise zerorange interactions. This work demonstrates that $N$body systems with twobody zerorange interactions can be treated reliably and efficiently by the finite temperature and ground state path integral Monte Carlo approaches, using the exact twobody propagator for zerorange interactions in the pair product approximation. The performance of the propagators is tested by reproducing known results for various one and threedimensional systems. We further calculate the energy and structural properties for the ground state of $N$ threedimensional bosons at unitary interacting via twobody zerorange and threebody repulsive potentials. [Preview Abstract] 

K1.00058: Isolated Monopoles in a Spinor BoseEinstein Condensate Michael Ray, Emmi Ruokokoski, Konstantin Tiurev, Mikko M\"{o}tt\"{o}nen, David Hall We present an update on our experiments detailing the observation of isolated monopoles in a spinor BoseEinstein condensate. Unlike the Dirac monopole [1], these point defects exist in the order parameter of the condensate wave function. With no associated line singularities they also represent truly isolated monopoles. We will discuss the underlying theory and present new data confirming the existence of this point defect. \\[4pt] [1] M.W. Ray, E. Ruokokoski, S. Kandel, M. M\"{o}tt\"{o}nen and D.S. Hall, Nature 505, 657 (2014). [Preview Abstract] 

K1.00059: Excitation spectrum of BoseEinstein Condensates with modified dispersion Maren Mossman, M.A. Khamehchi, Peter Engels BoseEinstein Condensates provide a flexible platform to model a wide variety of condensed matter phenomena. To this goal, Raman dressing schemes and dynamical lattices have emerged as a premier tool, allowing for a modification of the dispersion relation leading to spinorbit coupling and artificial gauge fields. Using Bragg spectroscopy, we investigate the collective excitation spectrum of BECs with engineered dispersion relations and study consequences of a rotonlike minimum that can be softened by changing Raman dressing parameters. We report on the current status and future directions of our experiments. [Preview Abstract] 

K1.00060: Magnetoassociation near an atomdimer resonance D. Luo, J.H.V. Nguyen, R.G. Hulet Over the past decade the universal scaling of Efimov trimers has been explored in various atomic species by measuring the threebody loss coefficient. An enhancement of the threebody loss at the atomdimer resonance has been observed,\footnote{S.E. Pollack, D. Dries, \& R.G. Hulet, Science, 326, 1683 (2009) }$^{,}$\footnote{M. Zaccanti et al. Nature Physics, 5, 586 (2009)} but remains unexplained. It has been attributed to an ``avanlanche mechanism'' based on resonant atomdimer scattering, yet the effectiveness of the hypothesis is under scrutiny.\footnote{J. Schuster et al. Phys. Rev. Lett. 87, 170404 (2001) }$^{,}$\footnote{M. Hu et al. Phys. Rev. A 90, 013619 (2014)} We present a new piece to the puzzle. In our work, Feshbach dimers and Efimov trimers are formed near the atomdimer resonance by RFassociation, from a BoseEinstein condensate of $^7$Li atoms. The molecular binding energies are tunable by the broad Feshbach resonance of the atoms in the $1,1\rangle$ state. We observe that the dimer formation rate is significantly enhanced at the atomdimer resonance. The origin of this enhanement is unclear, but it may be closely related to the enhancement of the threebody loss rate. [Preview Abstract] 

K1.00061: Diffuse light scattering from a dense and cold microscopic $^{87}$Rb sample Kasie Kemp, S.J. Roof, M.D. Havey, I.M. Sokolov, D.V. Kupriyanov We report investigation of nearresonance light scattering from a cold atomic sample of $^{87}$Rb. Measurements are made on the $F=2\to F'=3$ nearly closed hyperfine transition for atomic densities ranging from $\sim10^{10}$ to $\sim10^{13}$ atoms/cm$^3$. The sample, initially prepared in a magnetooptical trap, is loaded into a faroffresonance trap (FORT) in which the ensemble has a temperature $\sim$100 $\mu$K and initial Gaussian radii of $\sim$3 $\mu$m and $\sim$280 $\mu$m in the transverse and longitudinal directions, respectively. The experimental geometry consists of projecting a nearresonance collimated laser beam onto the entire volume of the FORT and detecting the diffusely scattered light. The measured scattered light intensity as a function of detuning, atomic density, and sample size suggests that collective light scattering plays an important role in the experimental results. [Preview Abstract] 

K1.00062: ATOM INTERFEROMETERS 

K1.00063: Development of an atomic gravimeter based on atom interferometer Taeg Yong Kwon, SangBum Lee, Sang Eon Park, MyoungSun Heo, HyunGue Hong, Chang Yong Park, WonKyu Lee, DaiHyuk Yu We present an atomic gravimeter under development at KRISS in Korea for precise measurement of absolute gravity. It is based on atomic interference of laser cooled $^{87}$Rb atoms in free fall. The temperature of the atoms is cooled to about 5 $\mu $K in a magnetooptic trap. Three Raman light pulses are applied for splitting, reflecting and recombining the atoms clouds while the atoms are in free fall. The pulse width and spacing time of Raman pulses is 40 $\mu $s and about 50 ms, respectively. During the interferometry, the frequency difference between the two counterpropagating Raman beams is chirped to compensate for Doppler shift induced by gravitational acceleration. The interference signals are measured at different spacing times to find the chirping rate at which the phase of interference fringe is independent of the spacing time. The chirping rate ($\approx $ 25.1 MHz/s) corresponds to g$\cdot$k$_{\mathrm{eff}}$/2$\pi $, where k$_{\mathrm{eff}} = $k1$+$k2 (k1 and k2 are wave numbers for two Raman beams). At present, we are going to introduce an antivibration platform and a magnetic shield for accuracy evaluation of the gravimeter. In the presentation, the preliminary results of the KRISS gravimeter will be discussed. [Preview Abstract] 

K1.00064: Atom Interferometer Technologies in Space for Gravity Mapping and Gravity Science Jason Williams, Shengwey Chiow, James Kellogg, James Kohel, Nan Yu Atom interferometers utilize the wavenature of atomic gases for precision measurements of inertial forces, with potential applications ranging from gravity mapping for planetary science to unprecedented tests of fundamental physics with quantum gases. The high stability and sensitivity intrinsic to these devices already place them among the best terrestrial sensors available for measurements of gravitational accelerations, rotations, and gravity gradients, with the promise of several orders of magnitude improvement in their detection sensitivity in microgravity. Consequently, multiple precision atominterferometerbased projects are under development at the Jet Propulsion Laboratory, including a dualatomicspecies interferometer that is to be integrated into the Cold Atom Laboratory onboard the International Space Station and a highly stable gravity gradiometer in a transportable design relevant for earth science measurements. We will present JPL's activities in the use of precision atom interferometry for gravity mapping and gravitational wave detection in space. Our recent progresses bringing the transportable JPL atom interferometer instrument to be competitive with the state of the art and simulations of the expected capabilities of a proposed flight project will also be discussed. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. [Preview Abstract] 

K1.00065: Planned Efficiency Measurements of STIRAP Vladislav Zakharov, Casey McKenna, Deqian Yuan, Jessica Gasparik, Harold Metcalf Our measurements of the absolute efficiency of using STIRAP to populate Rydberg states of He have been limited by the Doppler detuning associated with the divergence of the atomic beam that crosses perpendicular to our laser beams. The limitation is exacerbated when both laser beams copropagate, compounding these Doppler shifts. We plan to have them counterpropagate and thereby ameliorate this effect. He 2$^3$S atoms in a LN$_2$ temperature thermal beam are coupled to the 3$^3$P state by $\lambda$= 389 nm light (blue), and that state is coupled to Rydberg states by $\sim$ 800 nm (red) light. The antiparallel laser beams are arranged so that the atoms encounter the red light first (counterintuitive order for STIRAP) partially overlapping with the blue. We have observed interference among the atomic transitions by varying the light polarization,\footnote{Yuan Sun. PhD thesis, Stony Brook, 2013.} and are planning further studies concerning these internal atomic interferometry phenomena. [Preview Abstract] 

K1.00066: Cold Atom Gravity Gradiometer for Geodesy Alex Sugarbaker, Adam Black, Micah Ledbetter, Tao Hong, Mark Kasevich, Babak Saif, Scott Luthcke, Bernard Seery, Lee Feinberg, John Mather, Ritva KeskiKuha We are developing an atom interferometer gravity gradiometer for Earth science studies from a satellite in low Earth orbit. The target sensitivity of the gradiometer is $7 \times 10^{5}$ E/Hz$^{1/2}$ when extrapolated to operation in microgravity. This is two orders of magnitude beyond ESA's Gravity field and steadystate Ocean Circulation Explorer (GOCE), and would improve our ability to understand and monitor ocean currents, the thinning of ice sheets, magma flows, and other geophysical phenomena. Many of the techniques employed in this sensor were developed in the Stanford 10 m drop tower [S.M. Dickerson, {\it et al.}, Phys. Rev. Lett. {\bf 111}, 083001 (2013)]. [Preview Abstract] 

K1.00067: Synthetic Rotation of a BoseEinstein Condensate Michael Bromley, Mark Baker, Thomas Bell, Jake Glidden, Bryce Henson, Simon Haine, Tyler Neely, Nicholas McKay Parry, Halina RubinszteinDunlop, Matthew Davis, Marty Kandes, Ricardo CarreteroGonzalez We propose the synthetic rotation of BoseEinstein condensates as a means of prototyping rotation sensors based on atom inferometry using BoseEinstein condensates. The fundamental idea is to evaporatively cool and condense the atoms into the ground state of a rotating potential. We have designed and implemented an experimental BoseEinstein condensate system using an initial hybridstage of magnetic and optical trapping and cooling, followed by an alloptical condensation into a reddetuned laser potential that consists of a transverse lightsheet as well as a laser that rotates around from above. We will present our experimental progress towards the BoseEinstein condensation of atoms in the ground state of a rotating ringtrap potential. This system enables the future synthesis of various Sagnac effectbased atom inteferometry protocols to be tested when undergoing arbitrary rotation rates from Hz frequencies down to the rotation of the Earth. [Preview Abstract] 

K1.00068: FUNDAMENTAL CONSTANTS AND TESTS OF BASIC LAWS 

K1.00069: Progress toward a search for a coupling of the proton spin to gravity Derek Jackson Kimball, Jordan Dudley, Yan Li, Swecha Thulasi, Julian Valdez We present an overview of progress in our search for a hypothetical longrange coupling between rubidium (Rb) nuclear spins and the mass of the Earth [D. F. Jackson Kimball et al., Annalen der Physik {\textbf{525}}(7), 514528 (2013)], which can be interpreted as a search for a longrange monopoledipole interaction or a spingravity coupling. The experiment consists of simultaneous measurement of the spin precession frequencies of overlapping ensembles of Rb85 and Rb87 atoms contained within an evacuated, antirelaxationcoated vapor cell. Because of the nuclear structure of Rb85 and Rb87, the experiment is particularly sensitive to anomalous spindependent interactions of the proton [D. F. Jackson Kimball, arXiv:1407.2671 (2014)]. We have studied a number of important systematic effects related to vector and tensor light shifts, optical pumping effects, the ac and nonlinear Zeeman effects, magnetic field gradients, and the rotation of the Earth. We anticipate that our experiment can improve sensitivity to anomalous longrange spinmass couplings of the proton compared to previous experiments by more than an order of magnitude. [Preview Abstract] 

K1.00070: From Maxwell's Electrodynamics to Relativity, a Geometric Journey Felix T. Smith Since Poincar\'e and Minkowski recognized $ict$ as a fourth coordinate in a fourspace associated with the Lorentz transformation, the occurrence of that imaginary participant in the relativistic fourvector has been a mystery of relativistic dynamics. A reexamination of Maxwell's equations (ME) shows that one of their necessary implications is to bring to light a constraint that distorts the 3space of our experience from strict Euclidean zero curvature by a timevarying, spatially isotropic term creating a minute curvature $K_{\mathrm{curv}}(t)$ and therefore a radius of curvature $r_{\mathrm{curv}}(t)= K_{\mathrm{curv}}^{1/2}(t)$ (F. T. Smith, Bull. Am. Phys. Soc. 60, \#2, Abstr. V1.00294, March, 2015). In the light of MichelsonMorley and the Lorentz transformation, this radius must be imaginary, and the geometric curvature $K$ must be negative. From the time dependence of the ME the rate of change of the curvature radius is shown to be $dr_{\mathrm{curv}}/dt=ic$, agreeing exactly with the Hubble expansion. The imaginary magnitude is the radius of curvature; the time itself is not imaginary. Minkowski's spacetime is unjustified. Important consequences for the foundations of special relativity follow. [Preview Abstract] 

K1.00071: Quantum Interference Effects in Saturated Absorption Spectroscopy of n=2 TripletHelium Fine Structure Eric A. Hessels, Marko Horbatsch, Alain Marsman The program of determining a more accurate value of the fine structure constant from He fine structure spacings requires the determination of linecenters to better than 1 kHz. Even though neighboring transitions are more than 1000 linewidths out of resonance, when measuring the linecenters to the required accuracy one cannot ignore the different available excitation and decay pathways, whose interference can lead to appreciable shifts. This effect was demonstrated to be significant in laser spectroscopy [1], and in saturated fluorescence spectroscopy [2]. Here, it is investigated for saturated absorption spectroscopy [3]. Our findings for the $2^{3}P_{1}$  $2^{3}P_{2}$ interval indicate that the extrapolations to zero laserfield intensity and zero gas pressure from the ranges at which experiments were performed introduce kHzlevel shifts. Correcting for these shifts moves the result into better agreement with other measurements of this interval.\\[4pt] [1] A. Marsman, M. Horbatsch, and E.A. Hessels, Phys. Rev. A 86, 040501(R) (2012)\\[0pt] [2] A. Marsman, E.A. Hessels, and M. Horbatsch, Phys. Rev. A 89, 043403 (2014)\\[0pt] [3] T. Zelevinsky, D. Farkas, and G. Gabrielse, Phys. Rev. Lett. 95, 203001 (2005) [Preview Abstract] 

K1.00072: ``Simplest Molecule'' Clarifies Modern Physics I. CW Laser SpaceTime Frame Dynamics Tyle Reimer, William Harter Molecular spectroscopy makes very precise applications of quantum theory including GPS, BEC, and laser clocks. Now it can return the favor by shedding some light on modern physics mysteries by further unifying quantum theory and relativity. We first ask, ``What is the simplest molecule?'' Hydrogen H$_{2}$ is the simplest stable molecule. Positronium is an electronpositron (e$^{+}$e$^{})$pair. An even simpler ``molecule'' or ``radical'' is a photonpair ($\gamma $, $\gamma )$ that under certain conditions can create an (e$^{+}$e$^{})$pair. To help unravel relativistic and quantum mysteries consider CW laser beam pairs or TEwaveguides. Remarkably, their wave interference immediately gives Minkowski spacetime coordinates and clearly relates eight kinds of spacetime wave dilations or contractions to shifts in Doppler frequency or wavenumber. Modern physics students may find this approach significantly simplifies and clarifies relativistic physics in spacetime (x,ct) and inverse timespace ($\omega $,ck). It resolves some mysteries surrounding superconstant c$=$299,792,458m/s by proving ``Evenson's Axiom'' named in honor of NIST metrologist Ken Evenson (19322002) whose spectroscopy established c to start a precision renaissance in spectroscopy and GPS metrology. [Preview Abstract] 

K1.00073: ``Simplest Molecule'' Clarifies Modern Physics II. Relativistic Quantum Mechanics William Harter, Tyle Reimer A ``simplest molecule'' consisting of CW laser beam pairs helps to clarify relativity from poster board  I. In spite of a seemingly massless evanescence, an optical pair also clarifies classical and quantum mechanics of relativistic matter and antimatter. Logical extension of (x,ct) and ($\omega $,ck) geometry gives relativistic action functions of Hamiltonian, Lagrangian, and Poincare that may be constructed in a few rulerandcompass steps to relate relativistic parameters for group or phase velocity, momentum, energy, rapidity, stellar aberration, Doppler shifts, and DeBroglie wavelength. This exposes hyperbolic and circular trigonometry as two sides of one coin connected by Legendre contact transforms. One is Hamiltonianlike with a longitudinal rapidity parameter $\rho $ (log of Doppler shift). The other is Lagrangelike with a transverse angle parameter $\sigma $ (stellar aberration). Optical geometry gives recoil in absorption, emission, and resonant RamanCompton acceleration and distinguishes Einstein rest mass, Galilean momentum mass, and Newtonian effective mass. (Molecular photons appear less bulletlike and more rocketlike.) In conclusion, modern spacetime physics appears as a simple result of the more selfevident Evenson's axiom: ``All colors go c.'' [Preview Abstract] 

K1.00074: A study of electrochemistry for Pathor Kuchi Leaf (PKL) electricity generation system Md. Kamrul Alam Khan, Md. Shamsul Alam, Jesmin Sultana, M.A. Mamun Electrodes are put into the \textit{Bryophyllum Pinnatum} Leaf (BPL) or Pathor Kuchi Leaf (PKL) sap and they produce substantially sufficient amount of electricity to power energy consumed electronics and electrical appliances. The role of CuSO$_{\mathrm{4}}$.5H$_{\mathrm{2}}$O solution has been studied. The electrical and chemical properties, a very important factor for PKL electricity generation device have been studied in this research work. The electrical properties are: internal resistance, voltage regulation, energy efficiency, pulse performance, self discharge characteristics, discharge characteristics with load, capacity of the PKL cell, temperature characteristics and life cycle of the PKL cell. The chemical properties are: The [Zn$^{\mathrm{2+}}$], [Cu$^{\mathrm{2+}}$] and quotient constant. The optimum level of the CuSO$_{\mathrm{4}}$.5H$_{\mathrm{2}}$O solution has been studied. The adherent/adherence effect of the electrodes for use in CuSO$_{\mathrm{4}}$.5H$_{\mathrm{2}}$O solution have been studied\textbf{.} The performance of the production of the two biproducts (fertilizer and hydrogen gas production) has been studied. Variation of concentration of Zn$^{\mathrm{2+}}$ and Cu$^{\mathrm{2+}}$ with the variation of percentage of the secondary salt (CuSO$_{\mathrm{4}}$. 5H$_{\mathrm{2}}$O), percentage of the water and the percentage of PKL sap have been studied. The change of PKL power efficiency with time has also been studied. Most of the results have been tabulated and graphically discussed. This study on showed that, internal resistance is nearly 0.60 ohm, voltage regulation is close to 9{\%}, pulse performance is so good and energy efficiency is about 65{\%}. Internal resistance is very much higher than the acceptable range. [Preview Abstract] 

K1.00075: QUANTUM GASES 

K1.00076: Performance of single qubit gates in an array of neutral atoms Yang Wang, Aishwarya Kumar, Xianli Zhang, Theodore A. Corcovilos, David S. Weiss We have demonstrated arbitrary single qubit gates on neutral atoms trapped in a 5$\times$5$\times$5 3D optical lattice. We will describe two types of gates, both based on a combination of Starkshifting target atoms with crossed optical beams and microwave pulses. Our poster will discuss gate quality, gate times, scalability issues and cross talk. [Preview Abstract] 

K1.00077: Quantum Process Tomography of a Room Temperature OpticallyControlled Phase Shift Connor Kupchak, Samuel Rind, Eden Figueroa We have developed a room temperature setup capable of optically controlled phase shifts on a weak probe field. Our system is realized in a vapor of $^{87}$Rb atoms under the conditions of electromagnetically induced transparency utilizing a $N$type energy level scheme coupled by three optical fields. By varying the power of the signal field, we can control the size of an optical phase shift experienced by weak coherent state pulses of $\langle n\rangle\sim1$, propagating through the vapor. We quantify the optical phase shift by measuring the process output via balanced homodyne tomography which provides us with the complete quadrature and phase information of the output states. Furthermore, we measure the output for a set of states over a subspace of the coherent state basis and gain the information to completely reconstruct our phase shift procedure by coherent state quantum process tomography. The reconstruction yields a rank4 process superoperator which grants the ability to predict how our phase shift process will behave on an arbitrary quantum optical state in the mode of the reconstruction. Our results demonstrate progress towards room temperature systems for possible quantum gates; a key component of a future quantum processor designed to operate at room temperature. [Preview Abstract] 

K1.00078: Quantum dynamics of a crossed cavity EIT system Bertus Jordaan, Phuong Nguyen, Carl Cheung, Chris Ianzano, Connor Kupchak, Eden Figueroa While much experimental progress has been made towards achieving quantum devices operating with single qubits, the development of lightmatter nodes in which deterministic twoqubit gates can be realized still remains an elusive goal. This is due to the difficulty to create strong photonphoton interactions. A possible solution to this challenge is the experimental implementation of multiple cavity modes strongly coupled to the same atomic ensemble. In this work we investigate the combined effects of cavity quantum electrodynamics (CQED) and electromagnetically induced transparency (EIT) in a doubly coupled lightmatter system. We have simulated EITbased N and Mtype atomic schemes in which fewphoton level probe and signal fields are both strongly coupled to an atomic ensemble. The dynamics of the system is obtained numerically by solving the Lindblad master equation for the atomcavities density operator. We will also show our experimental progress towards the implementation of this system using a rubidium ensemble simultaneously coupled to two optical cavities. [Preview Abstract] 

K1.00079: QUANTUM INFORMATION THEORY 

K1.00080: Shannon Information Entropy for TwoElectron Systems in Position Space Y.K. Ho, ChienHao Lin Entropic measures provide analytic tools to help us understand correlations in quantum systems. In our previous works, we have calculated linear entropy and von Neumann entropy as entanglement measures for ground state and lowerlying excited states in heliumlike systems [1]. Here in this work, we adopt another entropic measure, the Shannon entropy [2], to probe the nature of correlation effects. At the meeting we will show our results of Shannon entropy in position space for the singlet ground states of heliumlike systems including helium, positronium negative ion, hydrogen negative ion, and lithium positive ion, as well as results for systems with nucleus charge around the ionization threshold.\\[4pt] [1] Y.C. Lin, C.Y. Lin, and Y. K. Ho, \textit{Phys. Rev. A} \textbf{87}, 022316 (2013); C. H. Lin, Y.C. Lin, and Y. K. Ho, \textit{FewBody Syst.} \textbf{54}, 2147 (2013); C. H. Lin and Y. K. Ho, \textit{FewBody Syst.} \textbf{55}, 1141 (2014); C. H. Lin and Y. K. Ho, \textit{Phys. Lett. A} \textbf{378}, 2861 (2014);\\[0pt] [2] C. E. Shannon, \textit{Bell Syst. Tech. J.} \textbf{27}, 379 (1948). [Preview Abstract] 

K1.00081: Shannon information entropy in $N$ particles Moshinsky model Peng HsuanTung, Yew Kam Ho In the Moshinsky model, particles are confined in harmonic traps, and interparticle interaction is also of harmonic, the von Neumann entropy for such a system can be solved exactly [1], and the Shannon entropy of two particles Moshinsky model has been also investigated [2]. In our present work, we have extended the investigation on statistical correlation of $N$ particles Moshinsky model in the ground state by calculating Shannon information entropy in both position and momentum spaces as a function of numbers of particles, and of interaction strength among particles. We have solved the $N$ particles Moshinsky model wave function with analytical results, and with which Shannon information entropies for the whole system and that for a subsystem consists of $p$particle can analytically be computed. The mutual information in position and momentum spaces between a group of $p$particle in their ground state, and that of the other group for $N$$p$ particles, has also been determined. Our results are also used to test the entropic uncertainty principle, and found that such principle does hold in our system. At the meeting, in addition to the analytical results, we will also show an example for numerical results with $N =$ 8, and $p =$ 1 to 8. [1] P. Kos\`icik and A. Okopin\`iska, \textit{FewBody Syst.} \textbf{54}:16371640 (2013); [2] H. G. Laguna and R. P. Sagar, \textit{Phys. Rev. A} \textbf{84}, 012502 (2011). [Preview Abstract] 

K1.00082: Multimode Treatment of Coherent Photon Conversion Balakrishnan Viswanathan, Julio GeaBanacloche It has been suggested that secondorder optical nonlinearities (``coherent photon conversion'') could be used for quantum logic at the single photon level [1]. Specifically, succsessive twophoton processes in principle could accomplish the phaseshift (conditioned on the presence of two photons in the lowfrequency modes) $ 011 \rangle \longrightarrow 100 \rangle \longrightarrow 011 \rangle $. We have carried out a multimode study of this process using singlephoton wavepackets with different profiles (in particular, Gaussian and hyperbolic secant) in order to ascertain the fidelity achievable in such a process, both in free space [2] and with the nonlinear medium placed in a multiplyresonant cavity [3]. The fidelity achieved with a cavity was higher than what was achieved in free space. Our conclusion is that the desired phase shift cannot be accomplished with a fidelity greater than 0.5.\\[4pt] [1] N.K.Langford et al, Nature, Vol.478, 360 (2011)\\[0pt] [2] Julio GeaBanacloche, Phys.Rev.A, Vol. 81, 043823 (2010)\\[0pt] [3] Julio GeaBanacloche, Phys.Rev.A, Vol.87, 023832 (2013) [Preview Abstract] 

K1.00083: Optical Hyperentangled Bell State Analysis Nicholas LaRacuente, Paul Kwiat The ability to measure Bell states is essential throughout theories and experiments that separate quantum information from classical, and in applications such as optical quantum computing and communication. The lack of efficient nonlinear optics is a primary hindrance to Bell state analysis (BSA). While it is possible (using auxiliary photons) to perform qubit BSA with an arbitrary high probability of completely distinguishing the measured Bell state, this leaves an open question of whether auxiliaryenhanced BSA on hyperentangled or quditentangled photons is possible with sufficient accuracy and efficiency to be practical. We prove that in an ideal case, a single auxiliary pair can allow successful teleportation of a 2qubit hyperentangled Bell state with 1/16 probability of success; we then analyze the effect of more realistic auxiliary and primary pair production on this scheme. We argue that auxiliary enhancement will generalize to higher dimensional hyperentanglement and that it is possible to further increase the success rate with additional auxiliaries. Finally, we compare this method with quantum nondemolitionbased BSA and assess the practicality of packing more qubits into each photon for communication, computation and the study of quantum foundations. [Preview Abstract] 

K1.00084: Entropy Transfer of Quantum Gravity Information Processing Laszlo Gyongyosi, Sandor Imre We introduce the term smooth entanglement entropy transfer, a phenomenon that is a consequence of the causalitycancellation property of the quantum gravity environment. The causalitycancellation of the quantum gravity space removes the causal dependencies of the local systems. We study the physical effects of the causalitycancellation and show that it stimulates entropy transfer between the quantum gravity environment and the independent local systems of the quantum gravity space. The entropy transfer reduces the entropies of the contributing local systems and increases the entropy of the quantum gravity environment. We discuss the spacetime geometry structure of the quantum gravity environment and the local quantum systems. We propose the spacetime geometry model of the smooth entropy transfer. We reveal on a smooth Cauchy slice that the spacetime geometry of the quantum gravity environment dynamically adapts to the vanishing causality. We prove that the Cauchy area expansion, along with the dilation of the Rindler horizon area of the quantum gravity environment, is a corollary of the causalitycancellation of the quantum gravity environment. [Preview Abstract] 

K1.00085: QUANTUM/COHERENT CONTROL 

K1.00086: Rydbergblockaded medium inside a highfinesse optical cavity Jiteng Sheng, Santosh Kumar, William Whiteneck, Jonathon Sedlacek, James Shaffer We present experimental and theoretical progress on a Rydbergblockaded atomic ensemble coupled to a highfinesse optical cavity. Theoretically, we analyze the role that the Rydberg blockade mechanism can play in synthesizing collective quantum states and nonclassical states of light in this system. We study the correlation of two photon emission in the case of two Rydberg excitations within the cavity. Experimentally, we show that a cold atomic cloud can be transported into a highfinesse optical cavity by using a focustunable lens and that a collective state can be created inside the cavity using Rydberg atom blockade. Future work to realize collective quantum states in the atomcavity experiment and study the interesting dynamics of the correlated photon emission will be presented. [Preview Abstract] 

K1.00087: Enhancing spin squeezing using weak measurement Mingfeng Wang, Weizhi Qu, Pengxiong Li, Han Bao, Yanhong Xiao Spin squeezed states (SSS) are recognized as the key resource for precision measurements and quantum information processing. So far, the generation of such states is mainly based on quantum nondemolition (QND) measurement, which creates the degree of squeezing 1/(1 $ + \kappa^2$), where $\kappa$ is the coupling strength between light and atoms. In realistic systems, the coupling strength is often limited to a small value. Here we propose a novel scheme to enhance the coupling strength (and thus the spin squeezing) by using the weak measurement technique. We show that spinspin entanglement can be greatly enhanced by properly postselecting the final state of the photon that interacts with atoms via offresonant Faraday interaction. Our calculation shows that strongly squeezed spin states can be created with presently available techniques. [Preview Abstract] 

K1.00088: Quantum state estimation and feedback control aided by weak measurement reversal Hermann Uys, Pieter du Toit, Shaun Burd, Thomas Konrad We investigate state and frequency estimation of an oscillating qubit using weak POVM measurements. By employing a Fourier transform frequency estimator combined with a strategy of unitary reversal of the weak measurements, it is shown that for sufficiently strong measurements these reversals lead to improved frequency estimation. This approach opens new prospects for feedback control of qubit dynamics. [Preview Abstract] 

K1.00089: Polarization and amplitude probes in Hanle effect EIT noise spectroscopy of a buffer gas cell Shannon O'Leary, Aojie Zheng, Michael Crescimanno Noise correlation spectroscopy on systems manifesting Electromagnetically Induced Transparency (EIT) holds promise as a simple, robust method for performing highresolution spectroscopy used in applications such as EITbased atomic magnetometry and clocks. While this noise conversion can diminish the precision of EIT applications, noise correlation techniques transform the noise into a useful spectroscopic tool that can improve the application's precision. We study intensity noise, originating from the large phase noise of a semiconductor diode laser's light, in Rb vapor EIT in the Hanle configuration. We report here on our recent experimental work on and complementary theoretical modeling of the effects of light polarization preparation and postselection on the correlation spectrum and on the independent noise channel traces. We also explain methodology and recent results for delineating the effects of residual laser amplitude fluctuations on the correlation noise resonance as compared to other contributing processes. Understanding these subtleties are essential for optimizing EITnoise applications. [Preview Abstract] 

K1.00090: Ultrafast Pulse Sequencing for Fast Projective Measurements of Atomic Hyperfine Qubits Michael Ip, Anthony Ransford, Wesley Campbell Projective readout of quantum information stored in atomic hyperfine structure typically uses statedependent CW laserinduced fluorescence. This method requires an often sophisticated imaging system to spatially filter out the background CW laser light. We present an alternative approach that instead uses simple pulse sequences from a modelocked laser to affect the same statedependent excitations in less than 1 ns. The resulting atomic fluorescence occurs in the dark, allowing the placement of nonimaging detectors right next to the atom to improve the qubit state detection efficiency and speed. We also discuss methods of Doppler cooling with modelocked lasers for trapped ions, where the creation of the necessary UV light is often difficult with CW lasers. [Preview Abstract] 

K1.00091: Quantum Spin Gyroscope using NV centers in Diamond JeanChristophe Jaskula, Kasturi Saha, Ashok Ajoy, Paola Cappellaro Gyroscopes find wide applications in everyday life from navigation and inertial sensing to rotation sensors in handheld devices and automobiles. Current devices, based on either atomic or solidstate systems, impose a choice between longtime stability and high sensitivity in a miniaturized system. We are building a solidstate spin gyroscope associated with the NitrogenVacancy (NV) centers in diamond to overcome these constraints. More specifically, we will take advantage of the $^{14}$N nuclear spin coherence properties of NV centers and sidecollection techniques to achieve high sensitivity of about 1 $(mdeg\ s^{1})/\sqrt(Hz\ mm^3)$. Moreover, by exploiting the four classes of the NV axes, we will be able to determine axis of rotation as well as its rate. [Preview Abstract] 

K1.00092: Quantum Interference in Field Ionization of Rydberg Atoms Rachel Feynman, Jacob Hollingsworth, Michael Vennittilli, Tamas Budner, Ryan Zmiewski, Donald P. Fahey, Thomas J. Carroll, Michael W. Noel We excite ultracold rubidium atoms in a magnetooptical trap to a coherent superposition of three $m_j$ sublevels of a Rydberg state. After a delay in which the relative phase of the states evolve, we field ionize the atoms. The process of ionization is complicated by the details of the state structure for a weakly bound electron in Rydberg states. As these states ionize, their ionization pathways overlap, allowing them to interfere. We find that the result of this interference is dependent on the relative phase between the three states, and that the phase evolves in time inversely with the energy separation between the states. [Preview Abstract] 

K1.00093: Superresolution high sensitivity AC Magnetic Field Imaging with NV Centers in Diamond Erik Bauch, JeanChristophe Jaskula, Alexei Trifonov, Ronald Walsworth The NitrogenVacancy center in diamond (NV center), a defect consisting of a nitrogen atom next to a missing atom, has been successfully applied to sense magnetic field, electric field, temperature and can also be used as fluorescence marker and single photon emitter. We will present superresolution imaging of NV centers and simultaneous sensing of AC magnetic fields with high sensitivity. To demonstrate the applicability of superresolution magnetic field imaging, we resolve several NV centers with an optical resolution smaller than 20 nm and probe locally the gradient of a externally applied magnetic field. Additionally, we demonstrate the detection of magnetic field signals from $^1$H protons with subdiffraction image resolution. We will also show that our superresolution magnetometer will benefit from a new readout method based on a spintocharge mapping that we have developed to increase the readout contrast. [Preview Abstract] 

K1.00094: Fourier magnetic imaging with nanoscale resolution and compressed sensing speedup using electronic spins in diamond Keigo Arai, Chinmay Belthangady, Huiliang Zhang, Stephen DeVience, Nir BarGill, Paola Cappellaro, Amir Yacoby, Ronald Walsworth Opticallydetected magnetic resonance using nitrogen vacancy (NV) color centers in diamond is playing a leading role in nanoscale magnetic field imaging of various physical and biological samples at room temperature. NV magnetic imaging techniques to date, however, are based on ``real space'' detection, which is either limited by optical diffraction or requires slow scanning for nanometerscale resolution. Here we present an alternative approach of NV Fourier magnetic imaging. By employing pulsed magnetic field gradients, spatial information about the NV centers as well as the local magnetic field are phaseencoded in wavenumber or ``kspace.'' A Fourier transform then yields realspace images with nanoscale resolution, wide fieldofview, and compressed sensing speedup. [Preview Abstract] 

K1.00095: Low Temperature Symmetric Dynamical Decoupling in NV Centers Linh Pham, Demitry Farfurnik, Andrey Jarmola, Zhihui Wang, Viatcheslav Dobrovitski, Ronald Walsworth, Dmitry Budker, Nir BarGill Increasing the coherence time of an arbitrary spin state is a major step toward enhanced quantum information and quantum sensing in variety of quantum systems. In this work, we explore several dynamical decoupling techniques in order to determine a robust protocol for increasing the coherence time of an ensemble of nitrogenvacancy (NV) centers. By optimizing experimental parameters and using a concatenated version of the XY8 dynamical decoupling sequence, we preserve a general spin state up to almost 30 ms at a temperature of 77 K. The concatenated sequence performs better than standard CPMG and XY sequences on an arbitrary spin state and thus may be immediately applied to enhance the sensitivity of nvbased magnetometers. Additional potential applications include quantum memory and interactiondominated dynamics. [Preview Abstract] 

K1.00096: Probing quantum dynamics of strongly interacting spin ensembles Georg Kucsko, Peter Maurer, Joonhee Choi, Norman Yao, Soonwon Choi, Michael Knap, Sarang Gopalakrishnan, Mikhail Lukin Ensembles of strongly interacting spins offer an attractive platform for the study of manybody quantum dynamics. We present detailed study of the electronic spin dynamics within a diamond sample with very high nitrogen vacancy (NV) concentration (?80 ppm). Due to the small distance between neighboring NV centers, the spinspin interactions dominate over decoherence. Furthermore, by utilizing dynamical decoupling techniques, it is possible to suppress decoherence and study manybody phenomena. In particular, we present investigation of the interplay between interactions and disorder in such a system. [Preview Abstract] 

K1.00097: NONLINEAR OPTICS 

K1.00098: Cold Cs atoms inside a hollowcore photoniccrystal fiber Christopher Haapamaki, Taehyun Yoon, Jeremy Flannery, Golam Bappi, Rubayet Al Maruf, Omar Alshehri, Michal Bajcsy Ensembles of quantum emitters, in particular ensembles of cold atoms, are an important platform for implementing optical nonlinearities potentially controllable by single photons, with applications ranging from classical and quantum information processing to studies of quantummechanical phenomena in condensed matter and atomic systems. The enhancement of lightmatter interaction is a crucial stepping stone for these nonlinearities and one of the ways to achieve it is by simultaneously confining photons and the atomic ensemble inside a hollowcore optical waveguide. In recent years, optical nonlinearities controlled by several hundred photons were demonstrated with lasercooled Rb atoms confined in a reddetuned dipole trap inside a hollowcore photoniccrystal fiber. Here, we report our progress on an experiment for trapping ensembles of lasercooled Cs atoms inside such fiber with magicwavelength dipole trap and discuss the outlooks of this system for implementing nonlinear optics with single photons, including possible ways to modify the photonic environment of a hollow optical waveguide to achieve further enhancement of lightmatter interactions. [Preview Abstract] 

K1.00099: Approach to a convenient and efficient CW laser for UV spectroscopy at 243 nm Ali Khademian, David Shiner Second harmonic generation (SHG) is one approach for generating a single frequency UV light source for various applications, including spectroscopy. We use a reliable and stable near IR diode laser and a periodically poled crystal in a convenient doubling cavity to generated single frequency blue at 486 nm (with 500 mW power). This provides the fundamental source for generating UV. We implemented improvements for controlling and locking our blue laser source and to allow tests of crystal lifetime. To extend this source to the UV, two methods for SHG are investigated. The first is ordinary phase matching, with drawbacks, such as walkoff and the need for dichroic coatings for separating the fundamental blue from generated UV. The second is quasi phasematching (QPM), which conveniently separates the blue and UV using a Brewster cut nonlinear crystal. Unfortunately the required first order periodically poled period is shorter than currently achievable. Third order QPM is thus required, which reduces the single pass efficiency by a factor of 9. We discuss these two possibilities for UV generation, including the choice of nonlinear crystals, the techniques for separating UV from blue, the anticipated theoretical efficiency and UV power scale, and the status of our efforts. [Preview Abstract] 

K1.00100: Measurement of strong electric fields using roomtemperature RydbergEIT Stephanie Miller, David Anderson, Christopher Holloway, Joshua Gordon, Georg Raithel We present a measurement of strong electric fields using roomtemperature RydbergEIT. In a vapor cell, we drive microwave transitions between $^{85}$Rb Rydberg states and use the resultant resonances as probes of the applied field. We focus on the 65D$_{5/2}$  66D$_{5/2}$ twophoton transition and model the spectra with a nonperturbative Floquet analysis, which provides information about the strong microwaveinduced n and $\ell$mixing effects on levels and excitation rates. We are able to measure fields up to $\sim$250 V/m to within $\sim$1$\%$ relative uncertainty. This is approximately 50 times higher in intensity than we have previously measured with this technique. We are also able to account for electric field inhomogeneities within the vapor cell by comparing the experimental line strengths to the calculated excitation rates. The accessible field range can be extended to even higher fields by utilizing transitions between lowerlying Rydberg states, where dipole moments generally are smaller and larger fields are needed to enter the strongfield regime. We also discuss how the sensitivity of the method at small fields can be enhanced by analyzing minute changes of the EITsignatures that occur at fields much lower than where AutlerTownes splitting occurs. [Preview Abstract] 

K1.00101: Nonlinear susceptibility past the limits of perturbation theory Andrew Spott, Andreas Becker, Agnieszka JaronBecker Understanding the accuracy and domain of the nonlinear index of refraction is a critical step toward understanding filamentation in the propagation of high intensity laser light. We have examined the nonperturbative limit of the nonlinear susceptibility of hydrogen by comparing ab initio calculations of the susceptibility with perturbative calculations performed within the same theoretical framework. To this end, we have studied the susceptibility at the driving frequency for a pulse [1], and the susceptibility for third and fifthharmonic generation [2]. Our results show that the perturbative series is no longer applicable at approximately $10^{13}$ W/cm$^2$. Instead, accurate models of hydrogen within this regime must be determined through a nonperturbative treatment of the field and the atom.\\[4pt] [1] A. Spott, A. JaronBecker and A. Becker, Phys. Rev. A {\bf 90}, 013426 (2014);\\[0pt] [2] A. Spott, A. Becker, and A. JaronBecker, Phys. Rev. A (in press). [Preview Abstract] 

K1.00102: Resolving Airborne Particulate Concentration Inhomogeneities with a Schlieren Optical Technique Alexis Payne, Alem Teklu, Mike Larsen Our project explored the influence turbulence has on particulate clustering via use of the Schlieren Photographic technique. We successfully constructed the Schlieren optical set up, which consisted of a HeNe laser and a high speed CCD. We obtained data of turbulence of varying degrees affecting smoke particulates. The diffraction pattern in the data was clearly evident. We successfully denoised the images and calculated the 2D Fast Fourier Transform of the data. Analysis of the data has revealed interesting connections between turbulence and particle clustering. [Preview Abstract] 

K1.00103: ATOM AND MATTER OPTICS 

K1.00104: Relationship between twoand threephoton coherence in a laddertype atomic system YoonSeok Lee, HeungRyoul Noh, Han Seb Moon We investigated the relationship between twoand threephoton coherence in terms of the transition routes and coupling field intensities in a Dopplerbroadened laddertype atomic system of the 5S$_{1/2}$5P$_{3/2}$5D$_{5/2}$ transition in $^{87}$Rb atoms. Threephoton electromagnetically induced absorption (TPEIA) due to threephoton coherence was observed in the only transition route that exhibited a dominant twophoton coherence effect. We showed that twophoton coherence is a necessary condition for threephoton coherence phenomena. A comparison of the relative magnitudes of the electromagnetically induced transparency and TPEIA as a function of the coupling field intensity revealed that threephoton coherence increased twice as rapidly as twophoton coherence. Considering threephoton coherence in a Dopplerbroadened laddertype threelevel atomic system, the relation between twoand threephoton coherence was numerically calculated. [Preview Abstract] 

K1.00105: Highcontrast fourwave mixing in resonance doubleLambda atomic system Taek Jeong, Han Seb Moon We have observed fourwave mixing(FWM) of weak pumping in a resonance doubleLambda system for the 5S$_{\mathrm{1/2}}$5P$_{\mathrm{1/2}}$ transition of $^{\mathrm{87}}$Rb atoms, using weak pump intensity. When three beams(CPT1, CPT2 and pump) were copropagated in the doubleLambda configuration composed of the common excited state 5P$_{\mathrm{1/2}}$(F$_{\mathrm{e}}=$2) and the two ground states 5S$_{\mathrm{1/2}}$(F$_{\mathrm{g}}=$1 and 2), we directly measured the generated FWM signal filtering the three beams using polarizer and etalon filters. The spectral width of FWM signal was measured to be 5kHz under the condition of coherent population trapping(CPT). Dependence of FWM signals on the intensities of the two beams related CPT and pump beam was investigated in detail. [Preview Abstract] 

K1.00106: Ballistic atom pumps Andrwe Pyle, Tommy Byrd, Megan Ivory, Kevin Mitchell, Kunal Das, Seth Aubin, John Delos Researchers have long been interested in electron transport through mesojunctions containing timedependent potential barriers, a process often called ``quantum pumping.'' A useful model of such a system is a ballistic atom pump: two reservoirs of neutral ultracold atoms connected by a channel containing oscillating repulsive potentialenergy barriers. We report on experimental plans and progress to observe pumping dynamics with a freely propagating $^{87}$Rb BEC directed at a tightly focused bluedetuned laser beam. Classically, this system can create net particle transport in either direction, and, even if there is no net particle transport, energy can be pumped out of or into each reservoir. Such pumps can also heat or cool one or both reservoirs. In a quantum mechanical description of the pump, we find that the momenta of the particles scattered by the pump acquire multiple Floquet sidebands, while mostly respecting the range of classically allowed energies. Semiclassical and quantum simulations of the scattering process are in good agreement. Initial experimental efforts are directed at observing the Floquet momentum sidebands of the BEC. [Preview Abstract] 

K1.00107: STRONGFIELD PHYSICS 
(Author Not Attending)

K1.00108: Photon momentum sharing in strong field photoionization Andre D. Bandrauk In a recent experiment [1] it has been shown that there is unequal photon momentum sharing between absorbed photons and electrons at high intensities. The experimental results can be interpreted as the breakdown of the dipole approximation at intensities $\sim$ 10$^{14}$W/cm$^2$ and IR wavelengths much larger than atomic sizes 2a0$=$0.106 nm [2]. We show analytically and through nonperturbative quantum simulations that very different partitioning of photon momentum occurs in onephoton ionization as compared to multiphoton processes.This suggests there is a rich unexplored electronion dynamics and physics generated with current ultrafast intense lasers.\\[4pt] [1] CTL Smeenk et al, Phys Rev Lett 106, 193002(2011)\\[0pt] [2] S Chelkowski, AD Bandrauk, PB Corkum, Phys Rev Lett 113,263005(2014). [Preview Abstract] 

K1.00109: Cooper minima in electron spectra after multiphoton abovethreshold ionization Dmitry A. Telnov, ShihI Chu We have performed calculations of electron momentum and energy distributions after multiphoton abovethreshold ionization (ATI) for several oneelectron quantum systems (H, He$^{+}$, H$_{2}^{+}$, and HeH$^{2+}$) in intense laser fields. We use the carrier wavelengths in the nearinfrared band (730 to 800 nm) and the peak intensities $5\times 10^{13}$ to $1\times 10^{14}$ W/cm$^{2}$. For some initial states of the systems under consideration, the spectra exhibit minima in the lowenergy region (3 to 7 eV), which resemble the famous Cooper minima in onephoton ionization processes. The minima are well pronounced for the initial states with the electronic orbitals that have nodal surfaces, such as $2s$ state of He$^{+}$, $1\sigma_{u}$ state of H$_{2}^{+}$, and $2\sigma$ state of HeH$^{2+}$. Such minima are not observed for the initial ground electronic states, as well as for initial $2p$ state of He$^{+}$, which possess nodeless orbitals. The effect is essentially nonperturbative; the positions of the minima depend on the intensity and frequency of the laser field. Nonetheless, it seems the nodal structure of the initial electronic orbital plays a crucial role in shaping these minima in the ATI electron spectra. [Preview Abstract] 

K1.00110: Subcycle dynamics of high harmonic generation in valenceshell and virtual states of Ar atoms excited by attosecond pulses and driven by nearinfrared laser fields: A selfinteractionfree TDDFT theoretical approach John Heslar, Dmitry A. Telnov, ShihI Chu In the framework of the selfinteractionfree timedependent density functional theory (TDDFT), we have performed an ab initio allelectron study of subcycle structure, dynamics, and spectra of high harmonic generation (HHG) processes of Ar atoms in the presence of extreme ultraviolet (XUV) attosecond pulses and nearinfrared (NIR) laser fields. The TDDFT equations are solved accurately and efficiently via the timedependent generalized pseudospectral (TDGPS) method. We focus on the subcycle (with respect to NIR field) temporal behavior of the level shift of the excited energy levels and related dynamics of harmonic photon emission. We observe and identify the subcycle shifts in the harmonic emission spectrum as a function of the time delay between the XUV and NIR pulses. We present and analyze the harmonic emission spectra from 3snp$_{0}$, 3p$_{0}$ns, 3p$_{1}$nd$_{1}$, 3p$_{1}$np$_{1}$, 3p$_{0}$nd$_{0}$, 3p$_{0}$np$_{0}$, and 3p$_{0}$ns excited states and the 3p$_{0}$4p$_{0}^{}$ virtual state as functions of the time delay. In addition, we explore the subcycle a.c. Stark shift phenomenon in NIR fields and its influence on the harmonic emission process. Our analysis reveals several novel features of the subcycle HHG dynamics and spectra as well as temporal energy level shift. [Preview Abstract] 

K1.00111: Triggering coherent electronic hole motion with strongfield pulses Stefan Pabst, HansJakob W\"orner We report about a very effective way to create coherent hole wave packets in atoms and molecules. In xenon, we demonstrate how strongfield pulses can trigger coherent spinorbit hole motion in the valence $5p$ shell via tunnel ionization. The degree of coherence between the ionic states $5p_{1/2}^{1}$ and $5p_{3/2}^{1}$ can be controlled by the pulse duration and driving wavelength. [Preview Abstract] 

K1.00112: Photoelectron Holography: Exploration of the Multiphoton Ionization and Multiple Rescattering in Intense Laser Fields ChonTeng Chu, PengCheng Li, ShihI. Chu We perform a fully ab initio investigation of the multiphoton ionization (MPI) and electron multiple rescattering dynamics of atomic H driven by intense ultrashort midIR laser fields. The timedependent Schr\"{o}dinger equation is solved accurately and efficiently by means of the timedependent generalized pseudospectral method (TDGPS) in the KramersHenneberger (KH) frame. We use the semiclassical approach to analyze and visualize all the trajectories during the atomlaser interaction, unveiling the multiple eparent ion rescattering processes. In this way, we can identify the dominant behaviors of different parts of photoelectron holography to a particular number of times of the electron's revisits to its parent ion. [Preview Abstract] 

K1.00113: NuclearElectronic Coherence in StrongField Dissociative Ionization Youliang Yu, Yujun Wang, Shuo Zeng, B.D. Esry In strongfield dissociative ionization of molecules, the ionization step is usually modeled since direct calculation is very challenging. In most of the models used to date, ionization is assumed to occur at several welldefined times accompanied by promotion of a nuclear wave packet to the ionic BornOppenheimer potential. Whether these nuclear wave packets should add coherently or incoherently in general is an open question. To answer it, we solve the timedependent Schr\"odinger equation for onedimensional H$_2^+$, where ionization is included naturally, and compare the observables, such as the kinetic energy release spectrum, with those from an ionization model. We then examine the validity of such models in strongfield dissociative ionization of H$_2^+$ with reduced dimensionality. We do not, however, expect this physics to depend sensitively on the dimensionality. [Preview Abstract] 

K1.00114: Bohmian trajectory analysis of subcycle multiphoton ionization dynamics Hossein Z. Jooya, Dmitry A. Telnov, PengCheng Li, ShihI Chu An accurate 3D numerical scheme for the De BroglieBohm's framework of Bohmian mechanics is presented. This method is utilized to explore the subcycle multiphoton ionization dynamics of the hydrogen atom subject to intense near infrared (NIR) laser fields on the subfemtosecond time scale. The analysis of the timedependent electron density reveals that several distinct density portions can be shaped and detached from the core within a half cycle of the laser field. We identify several distinct groups of the Bohmian trajectories which are responsible for the multiple detachments of the electron density at different times. The method presented provides very accurate electron densities and Bohmian trajectories that allow to uncover the origin of the formation of the transient and distinct electron structures seen in the MPI processes. [Preview Abstract] 

K1.00115: Exploration of the dynamical origin of near and belowthreshold harmonic generation PengCheng Li, YaeLin Sheu, Cecil Laughlin, ShihI. Chu We report the finding of a new dynamic process of near and belowthreshold harmonic generation (HG) of cesium (Cs) atoms in a 3600nm midinfrared laser field. We find that the multiphoton dominated trajectories only involve the electrons scattered from the combined atomfield potential wall followed by the absorption of many photons in near and belowthreshold HG. Furthermore, only the belowthreshold HG near resonant structure involves the single dynamical phase which is almost constant at the different emission time, indicating that the dynamical phases are locked. We confirmed our findings by performing quantum and semiclassical analysis simultaneously. Our results provide a new understanding of the dynamic origin of the near and belowthreshold HG. [Preview Abstract] 

K1.00116: Generation of even belowthreshold harmonics by stretched H$_{2}^{+}$ molecules in intense elliptically polarized laser fields K. Nasiri Avanaki, Dmitry A. Telnov, ShihI. Chu We study the highorder harmonic generation(HHG) of H$_{2}^{+}$ molecular ions in intense nearinfrared elliptically polarized laser fields solving the timedependent Schr\"odinger equation by means of the timedependent generalized pseudo spectral method in prolate spheroidal coordinates. While the yield of abovethreshold harmonics for nonzero ellipticity is generally reduced as compared with linearly polarized fields, belowthreshold harmonics still appear quite strong except when the polarization plane is perpendicular to the molecular axis. Weak even harmonics are detected in the HHG spectra of stretched molecules, with the internuclear separations 7 to 9 a.u. This effect can be explained by the broken inversion symmetry due to dynamic localization of the electron density near one of the nuclei. Influence of the multiphoton resonances and twocenter interference on the HHG spectra is also analyzed. [Preview Abstract] 

K1.00117: Analysis of the Contribution of the Tunneling and Multiphoton regime in Highorder Harmonic Generation of H$_{2}^{+}$ K. Nasiri Avanaki, PengCheng Li, ShihI. Chu We present an \textit{ab initio} threedimensional precision calculation and analysis of highorderharmonic generation (HHG) of the hydrogen molecular ion subject to intense laser pulses employing the timedependent generalized pseudo spectral method in twocenter prolate spheroidal coordinates. The calculations are performed for the ground states of H$_{2}^{+}$ at the equilibrium internuclear separation $R = 2$ a.u. and different orientation angle. We utilized the spectral and temporal structures of the HHG and semiclassical calculations to explore the contribution of the tunneling and multiphoton (MP) process in the above threshold ionization regime in different part of the HHG plateau. We show that the HHG yields can be tuned by the alignment of the molecular ions to the laser polarization in which confirming the dependence of MP ionization and HHG on the orientation angle. The results uncovered several aspects of dynamical behavior of the electron on sub femtosecond time scale that is independent of the details of the molecular structures. [Preview Abstract] 

K1.00118: High suppression in strongfield ionization of laserirradiated molecule C$_{60}$ Vladimir Usachenko, Vyacheslav Kim, Pavel Pyak We report about the results of our theoretical study of strongfield (multiphoton) abovethreshold ionization (ATI) in laserirradiated carbon fullerene molecule C$_{60}$ under condition of relevant experiment [1]. The problem is addressed within the \textit{velocitygauge} (VG) formulation of molecular \textit{strongfield approximation} (SFA) [2] essentially exploiting the \textit{densityfunctionaltheory} (DFT) method for numerical composition of initial (laserfree) molecular state using the routines of GAUSSIAN03 code [3]. The results of our present VGSFA calculation demonstrate that ionization of C$_{60}$ is to be highly suppressed and reaches saturation at laser peak intensity $I \approx 2 \times 10^{14} W$/cm$^{2}$, in a perfect consistence with relevant experiment [1].\\[4pt] [1] M. Tchaplyguine \textit{et al. } J. Chem. Phys. \textbf{112}, 2781 (2000)\\[0pt] [2] V. I. Usachenko \textit{et al.} Phys. Rev. A \textbf{79}, 023415 (2009)\\[0pt] [3] M. J. Frisch and J. A. Pople. \textbf{Gaussian03, Revision A.1} (Gaussian, Inc., 2003 Pittsburgh, PA) [Preview Abstract] 

K1.00119: Strongfield abovethreshold ionization in laserirradiated C$_{60}$: The signatures of orbital symmetry and intramolecular interference Vladimir Usachenko, Vyacheslav Kim, Pavel Pyak We report about the results of our theoretical study of strongfield (multiphoton) abovethreshold ionization (ATI) in laserirradiated carbon fullerene molecule C$_{\mathrm{60}}$ under condition of relevant experiment [1]. The problem is addressed within the \textit{velocitygauge} (VG) formulation of molecular \textit{strongfield approximation} (SFA) [2] essentially exploiting the \textit{densityfunctionaltheory} (DFT) method for numerical composition of initial (laserfree) molecular state using the routines of GAUSSIAN03 code [3]. The results of our present VGSFA calculation for C$_{\mathrm{60}}$ photoelectron energy spectra (PES) demonstrate two distinct (wellseparated) and pronounced local interference minima  in the lowenergy and the highenergy domains of produced PES  both arising due to destructive \textit{intramolecular} (\textit{multislit}) quantum interference of strongfield ionization corresponding to photoelectron emission from multiple separate atomic centers.\\[4pt] [1] M. Tchaplyguine \textit{et al. } J. Chem. Phys. \textbf{112}, 2781 (2000)\\[0pt] [2] V. I. Usachenko \textit{et al.} Phys. Rev. A \textbf{79}, 023415 (2009)\\[0pt] [3] M. J. Frisch and J. A. Pople. \textbf{Gaussian03, Revision A.1} (Gaussian, Inc., 2003 Pittsburgh, PA) [Preview Abstract] 

K1.00120: Signatures of fieldinduced intramolecular quantum interference in highorder harmonic generation by laserirradiated homonuclear diatomics Vladimir Usachenko, Vyacheslav Kim, Pavel Pyak We report about the results of our theoretical study of the strongfield phenomenon of highorder harmonic generation (HHG) in homonuclear diatomics $H_{2}^{+}$ and$ H_{2}$ irradiated by a highintensity laser field of midinfrared wavelengths corresponding to intermediate values of the socalled \textit{Keldysh parameter} ($\gamma \le $1). The problem is addressed within the \textit{lengthgauge} (LG) formulation of \textit{strongfield} \textit{approximation }(SFA) [1] additionally exploiting the \textit{densityfunctionaltheory} (DFT) method for numerical composition of initial (laserfree) molecular state using the routines of GAUSSIAN03 code [2]. The results of our present LGVGA calculation well reproduce a pronounced interferencerelated minimum arising in highfrequency region of respective molecular HHG spectra and suggesting clear signatures of the fieldinduced \textit{intramolecular} interference [3] corresponding to photoelectron emission to intermediate continuum states from different atomic centers.\\[4pt] [1] M. Lewenstein \textit{et al.} \textit{Phys.Rev.A }\textbf{49}, 2117 (1994)\\[0pt] [2] M. J. Frisch and J. A. Pople. \textbf{Gaussian03, Revision A.1} (Gaussian, Inc., 2003 Pittsburgh, PA)\\[0pt] [3] J. Itatani \textit{et al. Nature (London) }\textbf{432~}, 867 (2004); J. P. Marangos, ibid. \textbf{435}, 435 (2005); T Kanai \textit{et al. } ibid. \textbf{435~}, 470 (2005). [Preview Abstract] 
(Author Not Attending)

K1.00121: Control of Attosecond Electron Diffraction by Elliptical LongWavelength Radiation Predrag Ranitovic, XiaoMin Tong, Daniel Hickstein, Margaret Murnane, Henry Kapteyn Generation of intense laser pulses in the midIR regime, has opened door for several novel applications in the ultrafast AMO physics. Attosecond electron diffraction and holography, driven by the midIR radiation is one example of these new developments. In this work we utilize a broad range of laser wavelengths (267 to 2000 nm) in a strongfield regime, to obtain holographic 2D images of electrons diffracting off small atoms and molecules. By comparing 2D electron momenta taken with different laser wavelengths, using a VMI geometry, we found that for the longwavelength laser pulses (1.3 and 2 um), the main features in the electron momenta come from the interference of the plane, and spherical electron wave packets diffracting off the parent ion. By controlling the ellipticity of the driving laser fields, we were able to tune the returning electron direction, and in turn the amplitudes of the diffracting spherical electron wave packets that carry the information of the electronion differential cross sections. In this combined theoretical and experimental work we showed how to control the amplitudes and the phases of these rescattering electron wave packets, and how to use this method to image matter with attosecond temporal and Angstrom spatial resolution. [Preview Abstract] 

K1.00122: Strong field ionization in a singlecycle pulse Baochun Yang, Francis Robicheaux We theoretically investigate the ionization of Rydberg atoms by a singlecycle pulse, and also its implications for the strong field ionization of ground state. The required threshold field amplitude (for 10\% ionization probability) scales inversely with the binding energy of initial states and also the pulseduration square when the pulse duration becomes much shorter than the classical Rydberg period. A simple model is introduced to understand this threshold behavior, where the nonzero displacement induced by a singlecycle pulse plays a critical role. By combining with the adiabaticionization threshold in the lowfrequency limit, an ionization window is expected for the ionization of different states. The ionizationprobability curve exhibits a ``ripple'' structure as a function of the pulse duration and the field amplitude, which is sensitive to the angular distribution of initial states. The observation of larger emittedelectron energy for the ionization of lowerlying Rydberg states in a recent experiment [S Li and R. R. Jones, Phys. Rev. Lett. 112, 143006 (2014)] is confirmed in our calculations for both sodium and hydrogen atoms. The differences between the ionization dynamics in a singlecycle pulse and that in a multicycle pulse are also discussed and presented. [Preview Abstract] 

K1.00123: Stable states in a strong IR field Changchun Zhong, Francis Robicheaux It is found that 10{\%} of atoms stay in the quasistable states after being exposed to intense laser or microwave (MW) pulses, even though the pulses' intensity is much stronger than that needed for static fields ionization. The reason why atoms survive those strong pulses has attracted growing attentions. A. Arakelyan et al. [1] have observed the optical spectra of the surviving Lithium atoms after interaction with intense 38GHz MW fields for more than 1000 cycles, and the spectra exhibit a periodic train of peaks 38GHz apart. It suggests that those weakly bound Rydberg electrons seldom go back to the ionic core, where the cycle average energy exchange happens. In this study, we are interested in the electron behavior in the presence of intense infrared fields with a much shorter wavelength (1000nm). By solving the full 3D time dependent Schrodinger equation, we calculate the spectra of the surviving atoms under intense IR fields. Our numerical calculations show atoms survive the intense field in quasistable states for a long time, and the optical spectra are obviously modulated by the IR frequency. Through tuning the ponderomotive energy, we see how field parameters affect the behavior of electrons. Different atoms, such as Hydrogen, Helium, Lithium, and Sodium, are tested to see how atom's energy structures influence the results. \\[4pt] [1] A. Arakelyan et al. Physical Review A 90, 013413 (2014) [Preview Abstract] 

K1.00124: Excitation Energy Dependence in Near Threshold AtomMicrowave Interaction Eric Magnuson, Vincent Carrat, Tom Gallagher When laser excitation of an atom occurs in the presence of a strong low frequency field, the final atomic state distribution depends on the energy of the laser excitation and the phase of the low frequency field when the excitation occurs. We explore how this phase dependence varies with laser excitation energy and microwave field amplitude. The excitation CW laser is tunable in an 80 GHz range centered on the ionization limit, and is amplitude modulated synchronously with a microwave field. Surviving bound atomic states of n $>$ 150 are detected. Although we find bound final states are most probable when the excitation laser frequency is an integer number of microwave photons from the limit, the phase dependent contrast of the signal does not strongly depend on whether the laser is tuned to these resonances. We observe that the microwave field amplitude which maximizes the signal's phase dependence varies continuously with excitation laser frequency. In addition, we observe the microwave phase when ionization is most probable shifts by 180 degrees as the laser frequency crosses the ionization limit. This suggests one phase maximizes energy transfer, ionizing electrons excited below threshold and capturing electrons excited above threshold. [Preview Abstract] 

K1.00125: Competing parallel and perpendicular dissociation pathways of CS$^{2+}$ in a strong laser field\textsuperscript{*} T. Severt, M. Zohrabi, M. Hastings, U. Ablikim, K.J. Betsch, Ben Berry, Bethany Jochim, G.S.J. Armstrong, D. Wilson, K.D. Carnes, C. TralleroHerrero, B.D. Esry, I. BenItzhak, T. Uhl\'{I}kov\'{a} We investigate the competition between parallel and perpendicular transitions in the strongfield dissociation of CS$^{2+}$. The dominant dissociation pathway is understood to be a onephoton perpendicular transition from the X$^3\Pi$ to the A$^3\Sigma^$ state. We hypothesize that the parallel component is due to a vibrational excitation to the continuum of the X$^3\Pi$ electronic state, driven by a permanentdipole transition. The dependence of this parallel transition's probability on the molecule's kinetic energy release as well as on the laser's pulse duration, intensity, and wavelength is explored. \\[4pt] \textsuperscript{*}Supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. MH was partially supported by NSFREU under Grant No. Phy1157044. BJ is supported by DOESCGF under Grant No. DEAC0506OR23100. DW is supported by NSFGRF under Grant No. DGE1247193. TU is supported by GACR and MetaCentrum. [Preview Abstract] 

K1.00126: Inferring The Effective SingleElectron Dynamics in High Harmonic Generation from Time Dependent \textit{ab initio} Studies Chen Zhang, Wei Cao, Dan Haxton, William McCurdy We explore the spectrum and dynamics of the atomic and molecular HHG processes using the multiconfiguration time dependent HartreeFock (MCTDHF) method in the context of noble gas atoms and homonuclear diatomic molecules. This multielectron calculation reproduces experimentally observed spectra, and can be used to produce an effective singleelectron timedependent potential. This reduced effective potential in a manyelectron system shows the effect of manybody dynamics in the presence of a strong field causes the system to depart from a single electron approximation. [Preview Abstract] 

K1.00127: Generalized eikonal approximation for strongfield ionization Katarzyna Krajewska, Felipe Cajiao V\'elez, Jerzy Kami\'nski Strongfield ionization of atoms by short laser pulses is analyzed by means of the generalized eikonal approximation. This newly developed approach, in contrast to the ordinary eikonal approximation, avoids a singularity at the center of the Coulomb potential and, therefore, it allows for the treatment of rescattering phenomena in terms of quantum trajectories. Using this approach we demonstrate the appearance of coherent diffraction patterns in photoelectron energy spectra. We identify the conditions necessary to obtain such coherent patterns, with a decisive role played by the driving laser pulse. [Preview Abstract] 

K1.00128: Formation of excited neutral D* fragments from D$_2$ by a strong laser field Ben Berry, M. Zohrabi, Bethany Jochim, T. Severt, U. Ablikim, D. Hayes, Jyoti Rajput, Kanaka Raju P., Peyman Feizollah, K.D. Carnes, B.D. Esry, I. BenItzhak Excited neutral D* fragments from D$_2$ are produced by intense, ultrashort laser pulses ($585\,$fs). The kinetic energy release (KER) upon fragmentation is found to be very sensitive to laser parameters such as chirp, peak intensity, and pulse duration. Furthermore, using field ionization of highly excited D* fragments, we are able to determine the $n$ population in a range of excited states ($17\leq n\leq44$). Due to the long flight time to the detector (tens of $\mu$s), much of the initial excited population decays by spontaneous emission. We simulate this process in order to link the measured population to that created by the laser. On the technical side, we also present a scheme for determining the detection efficiency of an MCP detector for excited neutral atoms. [Preview Abstract] 

K1.00129: LaserCluster interaction in MidIR range Hyunwook Park, Zhou Wang, Pierre Agostini, Louis DiMauro We report an experimental study on high harmonic generation (HHG) from inert gas clusters in direct comparison with atomic gases. In the experiment, noble gas clusters, which are produced by a supersonic pulsed jet, interact with infrared lasers at moderate intensity and generate highorder harmonics. Harmonic yields are recorded as a function of cluster size in an optical spectrometer, and group delay measurements are conducted with RABBITT method. In the HHG amplitude measurements, we observed a fast increase of the yield with the size of the clusters, and slowdown when clusters are larger than a critical size. In the HHG phase measurements, we observed almost identical group delay of harmonics from the cluster comparing with the monomer, which supports three step model in harmonic generation from noble gas clusters. A 1D Lewenstein's model in a cluster is constructed with an assumption of partially delocalized electron behavior. [Preview Abstract] 

K1.00130: Gauge transformations in multichannel laserinteraction Hamiltonians G.S.J. Armstrong, B.D. Esry In our previous studies of molecular photodissociation, we solved the timedependent Schr\"{o}dinger equation in full dimensionality, casting the lasermolecule interaction in a lengthgauge form. The nuclear wave function is then expanded on a basis of symmetric top functions in the angular coordinates. However, a velocity gauge representation of the nuclear motion may be advantageous, and may reduce the number of partial waves required in the angular basis expansion. In molecular problems, the standard transformation between length and velocity gauge must take account of the presence of shortrange nonlinear radial dependence of the dipole. In problems involving a single channel, the shortrange behavior is not removed by the gauge transformation, leading to a shortrange mixedgauge Hamiltonian. Having derived the form of this Hamiltonian, we extend our analysis to multichannel problems, where the gauge transformation is further complicated by offdiagonal dipole terms. We examine the impact of this transformation in fulldimensional calculations, particularly its effectiveness in reducing the required size of the angular basis. This work is supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S.A. [Preview Abstract] 

K1.00131: Development and application of accurate analytical models for single active electron potentials Michelle Miller, Agnieszka JaronBecker, Andreas Becker The single active electron (SAE) approximation is a theoretical model frequently employed to study scenarios in which innershell electrons may productively be treated as frozen spectators to a physical process of interest, and accurate analytical approximations for these potentials are sought as a useful simulation tool. Density function theory is often used to construct a SAE potential, requiring that a further approximation for the exchange correlation functional be enacted. In this study, we employ the Krieger, Li, and Iafrate (KLI) modification to the optimizedeffectivepotential (OEP) method to reduce the complexity of the problem to the straightforward solution of a system of linear equations through simple arguments regarding the behavior of the exchangecorrelation potential in regions where a single orbital dominates. We employ this method for the solution of atomic and molecular potentials, and use the resultant curve to devise a systematic construction for highly accurate and useful analytical approximations for several systems. [Preview Abstract] 

K1.00132: Effective HartreeEinstein Equation for the Relativistic Dynamics of the Trojan Wave Packets Matt Kalinski We find the high accuracy interpolating function for the relativistic energymomentum relation in the classical nonrelativistic form as the ratio of the normal momentum square and the momentum dependent effective mass. The relation has the proper behavior in the short and long momentum wave vector limit. The counterintuitive factor of 2 is found to obtain the accurate dispersion relation. Based on this relation and using the hydrodynamic approach to quantum mechanics we construct the effective nonlinear HartreeEinstein Schr{\"o}dinger equation containing the relativistic mass correction in the form of the effective mass dependent on the particle position through the quantum phase of the wave function. The equation allows to study of the dynamics of the nondispersing Gaussian Trojan Wave Packets in the relativistic limit in the scalar approximation only within the nonlinear Schr{\"o}dinger equation. We solve the selfconsistent equations for the coefficients of the generalized Gaussian wave function in harmonic approximation. Results are compared to the solutions of Dirac and KleinGordon equations and the numerical simulations are also performed to compare with the approximation. [Preview Abstract] 

K1.00133: PHOTOIONIZATION, PHOTODETACHMENT AND PHOTODISSOCIATION 

K1.00134: Photoejection with excitation in H$^{}$ and other systems A.K. Bhatia, R.J. Drachman Lymanalpha radiation, 1216Angstrom, has been seen from the sun and from various other sources. This radiation arises from the radiative transition from the 2p $^{2}$P state to 1s $^{2}$S state of the hydrogen atom. The $^{2}$P state can be excited from the 1s $^{2}$S state by electron impact. However, it is also possible to produce this excited state by photodetachment of the H$^{}$ ion, leaving the H atom in the $^{2}$P state. We have calculated cross sections for this process using Hylleraastype functions for the H$^{}$ ion and using the exchange approximation for the photoelectron in the final states of angular momentum equal to 0 and 2. The photoabsorption cross sections in H$^{}$ ions and He atoms leaving the hydrogen and helium in $^{2}$S are also calculated. Similar calculations have been carried out for the Li$^{+}$, Be$^{2+}$ and C$^{4+}$ ions. [Preview Abstract] 

K1.00135: Double Photoionization of Beryllium atoms using screening potential approximation Hari P. Saha We plan to report the results of our investigation on double photoionization of Beryllium atoms. We will present the results of triple differential cross sections at excess energy of 20 eV using our recently extended MCHF method [1]. We will use multiconfiguration Hartree Fock method to calculate the wave functions for the initial state. The final state wave functions will be obtained in the angle depended screening potential approximation [2,3] which accounts for electron correlation between the two final state continuum electrons. We will discuss the effect of core correlation in the triple differential cross section. The results will be compared with the available accurate theoretical calculations and experimental findings.\\[4pt] [1] Hari P. Saha, Phys. Rev. A 87, 042703 (2013).\\[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] 

K1.00136: Explanation of the recent results on photoionization of endohedral atoms Miron Amusia, Larissa Chernysheva, Eugeniy Drukarev We explain the recently observed discrepancy between experimental and theoretical results on ionization of atoms, encapsulated into the fullerenes by photons with the energies of about 80190$e$V [1]. Calculations strongly overestimated the experimental data. This is a manifestation of very low probability of photoionization without an inelastic process in the fullerenes shell (FS) at relatively high photon energies [2]. We demonstrate that photoionization of the caged atom without excitation of FS has a low probability also at intermediate and low photon energies. Very important consequence of this results is that description of interaction of the photoelectron with the FS by a simple effective potential is not justified even at energies of several dozens of eV. The large role of the inelastic processes prompts that it should be rather an optical potential, similar to that employed in nuclear physics.\\[4pt] [1]. R. A. Phaneuf, A. L. D. Kilcoyne, N. B. Aryal et al, Rhys. Rev. A \textbf{88}, 053402 (2013).\\[0pt] [2] M. Ya. Amusia and E. G. Drukarev, Phys. Rev. A \textbf{89}, 013412 (2014). [Preview Abstract] 

K1.00137: Photoionization microscopy in terms of local frame transformation theory P. Giannakeas, F. Robicheaux, C.H. Greene Twophoton ionization of an alkalimetal atom in the presence of a uniform electric field is investigated using a standardized form of the local frame transformation and generalized quantum defect theory. The relevant longrange quantum defect parameters in the combined Coulombic plus Stark potential are calculated with eigenchannel Rmatrix theory applied in the downstream parabolic coordinate $\eta$. The present formulation permits us to express the corresponding microscopy observables through the local frame transformation, and it gives a critical test of the accuracy of the HarminFano theory. [Preview Abstract] 

K1.00138: Enhancement of Xray Energy Deposition via Heavy Element Sensitization in Biological Environments Sara Lim, Anil Pradhan, Sultana Nahar, Rolf Barth Energy (dose) deposition by low vs. high energy xrays (LEX \& HEX), approximately E $\sim$ 100 keV and E $>$ 1 MeV respectively, was studied in biological matter sensitized with heavy elements (highZ or HZ) to improve radiation therapy of cancer. Computations and simulations show that LEX interact favorably with HZ sensitizers by depositing more dose than HEX. LEX photons effectively photoionize deep inner electronic shells and release cellkilling Auger electrons near malignant cells embedded with HZ atoms. HEX photons predominantly Compton scatter with little interaction, even with HZ elements. Monte Carlo simulations show that in comparison to unsensitized tissue, LEX irradiation of HZsensitized models resulted in up to a factor of 2 increase in dose deposition relative to HEX. To validate the studies, {\it in vitro} experiments were performed using 2 distinct cancer cell types treated with Ptbased sensitizers, then irradiated with a LEX 160 KV xray source and a HEX 6 MV LINAC employed in radiation therapy. The experiments support numerical simulations, and demonstrate several factors lower survival of HZsensitized cells irradiated with LEX compared with HEX [1].\\[4pt] [1] Lim, S. N. Heavy Element Radiosensitization in Xray Therapy. Thesis. Ohio State University, 2014 [Preview Abstract] 

K1.00139: Five Photon Double Ionization of Helium Ye Li, M. S. Pindzola, J. Colgan The five photon double ionization of the He atom is investigated in the photon energy range of 15.0 eV to 19.0 eV using a timedependent closecoupling method. The five photon double ionization cross section is found to exhibit resonance peaks corresponding to four photon excitation of the n=2 and n=3 subshells of He$^+$. At select photon energies near the n=2 and n=3 subshell resonance peaks, energy and angle differential cross sections are calculated using fixed intensity femtosecond light pulses, while energy and angle differential probabilities are also calculated using peaked intensity attosecond light pulses. [Preview Abstract] 

K1.00140: InnerShell Photodetachment of the Carbon Anions Chain Rene Bilodeau, Dan Gibson, Wes Walter, Ileana Dumitriu, Alejandro Aguilar, David Macaluso, Nora Berrah We have carried out innervalence and Kshell photodetachment experiments at the Advanced Light Source (LBNL) in stable homonuclear anions C$_{\mathrm{n}}^{\mathrm{}}$ (n$=$212) produced with a SNICS ion source. These measurements will be used to determine absolute cross sections and characterize the mechanisms that lead to different decay patterns such as nuclear dynamics resulting from photodissociation. The data will be compared to our previous Kshell photoionization data of atomic C$^{\mathrm{}}$ which revealed a shape resonance near 285 eV, in good agreement with an Rmatrix calculation. We will also present the branching ratios between the decay pathways as a function of cluster size to understand size dependent dynamical processes. This work is funded by the Department of Energy, Office of Science, Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under grant N. DEFG0292ER14299.A002 and in part by the National Science Foundation under Grant No. 1404109. [Preview Abstract] 

K1.00141: Photoionization of the 4d subshell of the La isonuclear sequence Sindhu Kalyadan, Hari R. Varma, P.C. Deshmukh, J.T. Costello, P. Hayden, S.T. Manson Photoionization studies along isonuclear sequences provide the required systematic data which are useful in many practical applications and also for testing the accuracy of various theoretical models [15]. In the present work, we report on 4d subshell photoionization studies of some of the members of La (Z$=$57) isonuclear sequence (La$^{3+}$, La$^{9+}$ and La$^{11+})$ using relativistic random phase approximation (RRPA) [6]. Photoionization cross sections, $\sigma $, angular distribution asymmetry parameters, $\beta$, and the individual dipole matrix elements for 4d$_{3/2}$ and 4d$_{5/2}$ subshells are presented along with the 4d branching ratios of these ions. It is found that in La$^{3+}$, the branching ratios show significant departure from the statistical value 1.5 due to the presence of Cooper minimum in the 4d $\to $ f ionization channels. This departure is minor for the case of La$^{9+}$ and La$^{11+}$ since the Cooper minimum in these cases occur in the discrete part of the 4d spectrum. \\[4pt] [1] J. Colgan, H. L. Zhang, and C. J. Fontes, Phys. Rev. A \textbf{77}, 062704 (2008). [2] C. E. Theodosiou, S. T. Manson, and Mitio Inokuti, Phys. Rev.A \textbf{34}, 943 (1986). [3] J. A. Shaw, \textit{et al}, Phys.Rev.A\textbf{ 63,} 032709 (2001). [4] J M Bizau \textit{et al}, Phys. Rev. Lett . 84, 435 (2000). [5] G B Pradhan J Jose , P C Deshmukh , V Radojevi\'c and S T Manson Phys. Rev. A \textbf{81} 063401 (2010). [6] W.R. Johnson and C D Lin Phys. Rev. A \textbf{20}, 964 (1979). [Preview Abstract] 

K1.00142: Kshell photoionization of Cl: Theory and experiment Zineb Felfli, Steven Manson, Alfred Msezane Recent measurements of the photoionization cross sections of atomic Cl in the vicinity of the 1s thresholds have been made [1] which have stimulated us to perform Rmatrix calculations wherein relativistic effects are taken into account \textit{via} the BreitPauli (BP) operator. The discrete wavefunctions are constructed with orbitals generated from a carefullychosen large scale configuration interaction (CI) expansion. The calculation, which also includes relativistic corrections, uses the CIV3 code of Hibbert [2] and Glass and Hibbert [3]. Owing to the openshell nature of the Cl atom there are actually four 1s thresholds, $^{3}$P$_{0,1,2}$ and $^{1}$P$_{1}$. The results are analyzed with particular focus on the resonances leading up to the four thresholds, and the various effects that dominate the cross sections in this energy range are disentangled. \\[4pt] [1] W. Stolte \textit{et al}, Phys Rev A \textbf{88}, 053425 (2013)\\[0pt] [2] A. Hibbert, \textit{Comput. Phys. Commun}. \textbf{9}, 141 (1975) \\[0pt] [3] R. Glass and A. Hibbert, \textit{Comput. Phys. Commun}. \textbf{16}, 19 (1978) [Preview Abstract] 

K1.00143: Photolysis of formic acid at 355nm Denhi Martinez, Teonanacatl Bautista, Alfonso Guerrero, Ignacio Alvarez, Carmen Cisneros Formic acid is well known as a food additive and recently an application on fuel cell technology has emerged. In this work we have studied the dissociative ionization process by multiphoton absorption of formic acid molecules at 355nm wavelength photons, using TOF spectrometry in reflectron mode (RTOF). Some of the most abundant ionic fragments produced are studied at different settings of the laser harmonic generator. The dependence of the products on these conditions is reported. [Preview Abstract] 

K1.00144: Relativistic Effects in the Photoionization of Very Heavy Atoms David A. Keating, Steven T. Manson, Pranawa C. Deshmukh At very high Z relativistic interactions become important contributors to even the qualitative nature of atomic properties. To explore the extent of relativistic interactions in the photoionization of a very heavy atom, a theoretical study of nobelium (Z$=$102) has been performed using the relativistic random phase approximation (RRPA) methodology [1]. In order to determine which features in the photoionization cross section are due to relativity, calculations using the (nonrelativistic) random phase approximation with exchange method (RPAE) [2] are performed for comparison. With the inclusion of interchannel coupling some relativistic effects are amplified or diminished. To distinguish which relativistic effects are native to the orbital of interest or a product of interchannel coupling, calculations have been performed with and without coupling for comparison. Aside from significant splitting and shifts of threshold, induced effects on subshells not strongly affected by relativity directly, e.g. outer shells, by inner subshells that are strongly affected, occur via changes in screening and interchannel coupling.\\[4pt] [1] W. R. Johnson and C. D. Lin, Phys. Rev. A 20, 964 (1979)\\[0pt] [2] M. Ya. Amusia, \textit{Atomic Photoeffect} (Plenum, NY, 1990). [Preview Abstract] 

K1.00145: Molecular Frame Photoelectron Angular Distributions for Core Ionization of CF$_4$ and C$_2$H$_2$F$_2$ C.S. Trevisan, J.B. Williams, A.J. Menssen, T.N. Rescigno, R. Dorner, C.W. McCurdy We present experimental and theoretical results for the angular dependence of electrons ejected from the core orbitals of tetrafluoromethane (CF$_4$) which display a tendency to avoid molecular bonds if averaged over directions of polarization of the incident Xray beam, in contrast to earlier cases (CH$_4$, H$_2$O and NH$_3$) studied by the same methods. To investigate whether the imaging effect can be used to detect the creation of core holes by photoionization from one of two atoms of the same type in a molecule, we computed and measured MFPADs of difluoroethylene (C$_2$H$_2$F$_2$). Good agreement with the experimentally measured angular distributions show that the MFPADs contain the clear signature of the corehole origin of the photoelectron, and validate the use of computed MFPADs as promising tools for the interpretation of such experiments. Our measurements employ the COLTRIMS method and the calculations were performed with the Complex Kohn Variational method. [Preview Abstract] 

K1.00146: Laser Vibrational Photodetachment Spectroscopy Near the Electron Affinity of S$_{2}$ John Yukich, Colin Tyznik, Jessica Barrick Numerous experiments have investigated the properties and dynamics of singleatom negative ions. Similar experiments may also be conducted with molecular anions. Laser photodetachment spectroscopy of such ions is more complex due to rotational and vibrational structure, but often yields spectroscopic benchmarks such as rotational constants and vibrational energies. In this experiment, photodetachment spectroscopy of the S$_{2}^{}$ anion is conducted over photon energies in the range of the S$_{2}$ electron affinity. The S$_{2}^{}$ anions are created by a twostep dissociative attachment process to a carrier gas of OCS. These anions are then stored in a Penning ion trap. The photodetachment is achieved with a widelytunable, singlemode, titanium: sapphire laser. Our results are consistent with a model adapted from previous studies of singleatom photodetachment, and also show evidence of successful evaporative cooling of the ion cloud. Future experiments will focus on highresolution detachment spectroscopy of these and other anions with an eye toward measurement of their molecular constants. [Preview Abstract] 

K1.00147: Innershell double photoionization of beryllium by intense Xray freeelectron laser pulses Samira Barmaki, Marc Andre Albert, Stephane Laulan We study the innershell double photoionization of the beryllium Be ($1s^{2}$ $2s^{2}$) by intense Xray freeelectron laser (XFEL) pulses. The inner and the outer shell of the atom are separated by a large energy gap; the ejection of the core electrons requires photon frequencies larger than 160 eV whereas photons of 1420 eV are sufficient to induce the double ionization of the $2s^{2}$ valence shell. In order to target only the core electrons, we use intense subfemtosecond laser pulses of photon frequencies above 170 eV so the ionization of the inner shell largely dominates that of the valence. Besides, the shortness of the pulses leaves no time for the relaxation of the outer shell to take place. The characteristics of the XFEL pulses allow us then to ``freeze'' the electrons of the valence by using a model potential, hence reducing the difficulty of the numerical investigation of the atom. In this case, the numerical study of Be becomes similar to our previous study on helium [1]. We present the results of the electron energy distribution of ejected core electrons under different laser parameters. \\[4pt] [1] S. Barmaki, P. Lanteigne and S. Laulan. Phys. Rev. A. 89, 063406 (2014). [Preview Abstract] 

K1.00148: Multiphoton dissociative ionization of CS$^+$ Jyoti Rajput, Bethany Jochim, M. Zohrabi, K.J. Betsch, U. Ablikim, Ben Berry, T. Severt, A.M. Summers, G.S.J. Armstrong, B.D. Esry, K.D. Carnes, I. BenItzhak We have studied the dissociative photoionization of a CS$^+$ molecular ion beam in the strongfield regime using $<$50 fs IR laser pulses ($\lambda\sim$790 nm) from a 10 kHz, $\sim$2 mJ (per pulse) Ti:Sapphire laser system. A coincidence threedimensional momentum imaging method was used to measure all ions and neutrals formed during this multiphoton process. Two prominent channels were observed: chargesymmetric dissociation, yielding C$^+$ + S$^+$, and chargeasymmetric dissociation, yielding C + S$^{2+}$. The differences between these two channels with reference to their relative production probability, energetics, and angular distributions is the focus of this work. [Preview Abstract] 

K1.00149: NearThreshold, VibrationallyResolved Photoionization of Molecular Nitrogen Gaetan VanGyseghem, Thomas Gorczyca, Connor Ballance Photoabsorption of molecular nitrogen (N$_2$) is investigated near the first ionization threshold using an Rmatrix, multichannel quantum defect (MQDT) approach. Building on an existing fixednuclei Rmatrix photoionization model [M. Tashiro, J. Chem. Phys. 132, 134306, (2010)], single and multiple configuration molecular descriptions have been considered using the UKRmol suite of codes. Photoionization cross sections, as well as reactance and dipole matrices, are first computed in the fixednuclei approximation. The smooth eigenquantum defects are parameterized as a function of electron scattering energy and internuclear separation for further MQDT rovibrational frame transformation calculations. Potential energy curves for the N$_2$ and N$_2^+$ states have also been constructed in order to assess the accuracy of the molecular structure. Comparison with highresolution experimental photoionization cross sections is also made near threshold, a region complicated by multiple vibrationallyresolved, interacting Rydberg series. [Preview Abstract] 

K1.00150: Electron correlation and relativistic effects in photoabsorption processes of heavy closed shell atoms: Intermediate shells of Mercury Tanima Banerjee, P.C. Deshmukh, S.T. Manson Accuracy in the study of the photoionization of heavy atomic systems requires the inclusion of both manybody effects (correlation) and relativistic interactions. The Relative Random Phase Approximation (RRPA) [1] is a powerful theoretical model which includes many important electron corrections, along with relativity, in the calculation of atomic photoionization. Previously, valence photoionization in atomic mercury has been investigated using RRPA [2]. To expand the understanding of the the correlation and relativistic effects further, photoionization of the intermediate subshells of atomic mercury, 4s, 4p, 4d, 4f, 5s and 5d, have been studied at different levels of truncations as a means of pinpointing the specific aspect(s) of correlation that is important in a given case. It has been found that the intermediate subshells are sensitive to the correlation and relativistic effects but not as significantly as in the case of valence shell photoionization. In this work we have systematically investigated the changes caused by relativistic and correlation effects on both dipole (E1) and quadrupole (E2) photoionization parameters for atomic mercury. \\[4pt] [1] W.R. Johnson and C.D. Lin, Phys. Rev. A \textbf{20}, 964 (1979).\\[0pt] [2] Tanima Banerjee, P. C. Deshmukh and S. T. Manson, Phys. Rev. A, \textbf{75}, 042701 (2007). [Preview Abstract] 

K1.00151: Electron correlation effects in time delay in photoionization process: Mercury Aarthi Ganesan, Soumyajit Saha, Ankur Mandal, Nerenda Nath Dutta, P.C. Deshmukh, S.T. Manson Relativistic and correlation affect time delay in the photoionization process [15]. Mercury, a heavy atom, requires the inclusion of both correlation and relativity. Time delay [6] in mercury is studied at various levels of approximation: (a) Relativistic Random Phase Approximation (RRPA) [8], (b) a modified version RRPA to include relaxation effects [9] (c) the relativistic multiconfiguration Tamm Dancoff approximation [10] to and (d) manybody perturbation theory [11]. Inclusion of interchannel coupling from the 5d subshell on the relativistic 6s channels reduces the time delay near the Cooper minima, along with the shift of the Cooper minima towards higher energy. A considerable change in time delay is expected due to the influence of relaxation, CI and polarization effects.\\[4pt] [1] M. Schultze, \textit{et al}, Science \textbf{328}, 1658 (2010). [2] A. S. Kheifets and I. A. Ivanov, , Phys. Review Lett. \textbf{105}, 233002 (2010). [3] A. S. Kheifets, Phys. Rev. A \textbf{87}, 063404 (2013). [4] P. C. Deshmukh, et al, Phys. Rev. A \textbf{89}, 053424 (2014). [5] Soumyajit Saha, et al, Phys. Rev. A \textbf{90}, 053406 (2014). [6] E.P. Wigner, Phys. Rev. \textbf{98}, 145 (1955) [7] W. R. Johnson and C. D. Lin, Phys. Rev. A \textbf{20}, 964\textbf{ }(1979). [8] V. Radojevic, M. Kutzner and H. P. Kelly, H P Phys. Rev. A\textbf{ 40} 727 (1989). [9] V. Radojevic and W. R. Johnson, Phys. Rev. A \textbf{31}, 2991 (1985). [10]\textit{ Manybody atomic physics}, J.J. Boyle and M.S. Pindzola, Cambridge University Press (1998). [Preview Abstract] 

K1.00152: Modification of a tandem massspectrometer for infrared multiphoton dissociation (IRMPD) of gasphase ions Julie M. Gillis, Sandra M. Osburn, Michael J. van Stipdonk, Theodore A. Corcovilos Infrared multiphoton dissociation (IRMPD) is a method of fragmenting molecular ions for structural analysis of the parent molecule. The target ions absorb many photons, increasing the vibrational state of the excited bonds until the dissociation occurs. We have modified a commercial linear quadrupole trap tandem mass spectrometer (ThermoFisher LTQ) by installing a removable highvacuum window in the rear accessory plate of the mass spectrometer. The window allows us to inject laser light into the ion trap. The shape of the injected laser beam is optimized to match the volume of the ion cloud within the ion trap, improving IRMPD efficiency. We present preliminary data of the IRMPD of weakly bound uranylacetone and uranyldimethyl sulfoxide clusters using a 20W pulsed $\mathrm{CO_2}$ laser (wavelength $10.6\,\mu m$), showing previously undetected fragmentation products. [Preview Abstract] 

K1.00153: Time delay in photoionization in Ne: Effect of different types of correlation Ankur Mandal, Soumyajit Saha, Narenda Nath Dutta, Aarthi Ganesan, P.C. Deshmukh, V.K. Dolmatov, A.S. Kheifets, S.T. Manson Various effects on time delay in photoionization, such as many body correlations, relativity, Cooper minima, autoionizing resonances, etc., [16] have been studied. Here we investigate the effects of correlation on time delay using relativistic randon phase approximation (RRPA) [7], RRPA with relaxation (RRPAR) [8] muticonfiguration Tamm Dancoff (MCTD) [9] (configuration interaction) and manybody perturbation theory (MBPT) [10]. Ne is chosen since it has been studied extensively. In an earlier study [5] a truncated RRPA calculation on Ne showed an increase in time delay near the 2s threshold as compared to a nonrelativistic calculation. In the present work, a full RRPA calculation is studied to explore the interchannel coupling effects in the vicinity of the 1s threshold. [1] M. Schultze, \textit{et al}, Science \textbf{328}, 1658 (2010). [2] K. Kl\"{u}nder, \textit{et al}, Phys. Rev. Lett. \textbf{106}, 143002 (2011). [3] A. S. Kheifets, Phys. Rev. A \textbf{87}, 063404 (2013). [4] P. C. Deshmukh, \textit{et al}, Phys. Rev. A \textbf{89}, 053424 (2014). [5] S. Saha, \textit{et al}, Phys. Rev. A \textbf{90}, 053406 (2014). [6] J. M. Dahlstr\"{o}m, \textit{et al}, Phys. Rev. A \textbf{86}, 061402 (2012). [7] W. R. Johnson and C. D. Lin., Phys. Rev. A \textbf{20}, 964 (1979). [8] V Radojevic, \textit{et al}, Phys. Rev. A \textbf{40} 727 (1989). [9] V Radojevic and W. R. Johnson, Phys. Rev. A \textbf{31}, 2991 (1985). [10] B. K. Mani, \textit{et al}, Phys. Rev. A \textbf{80}, 062505 (2009). [Preview Abstract] 

K1.00154: Photoionization of Au$^{+}$, Au$^{2+}$, and Au$^{3+}$ ions and developments in the synthesis of the metallofullerene Au@C$_{60}$ A.L. David Kilcoyne, Alfred Muller, Stefan Schippers, Jonas Hellhund, Alexander Borovik, Allison Mueller, Dylan Gross, Andrea Johnson, David Macaluso Absolute single photoionization of Au$^{+}$, Au$^{2+}$, and Au$^{3+}$ ions was investigated via the~mergedbeams technique at AMO Beamline 10.0.1.2 of the Advanced Light Source~at Lawrence Berkeley National Laboratory. The absolute single photoionization yield was measured as a function of photon energy for each species from the metastable state ionization threshold region to well above the ground state ionization potential. Additional highresolution measurements were performed for Au$^{+}$ and Au$^{2+}$ ions in the region of the ground and metastable state ionization thresholds to better resolve the detailed resonant structure found therein. This structure was used, along with the reported excited state energy levels of Au$^{+}$, to preliminarily identify previously unreported excitation levels in all three ions. In addition and as a component of the same program, photoionization studies of the endohedral metallofullerene Au@C$_{60}^{+}$ were performed using endohedral fullerene samples synthesized onsite at Beamline 10.0.1.2 of the ALS. [Preview Abstract] 

K1.00155: Absolute Photoionization of Br$^{+}$ and Rb$^{3+}$ Ions for the Determination of Elemental Abundances in Astrophysical Nebulae David Macaluso, Allison Mueller, Austin Kerlin, Dylan Gross, Manuel Bautista, Nicholas Sterling, Rene Bilodeau Recent observations have identified several transiron elements in astrophysical nebulae. The determination of elemental abundances in these nebulae provides insight into the processes of stellar nucleosynthesis which in turn contributes to our understanding of the chemical evolution of the Universe. However, determinations of these abundances are highly dependent on the availability of accurate atomic data. For many of the observed species, these data are either not well known or have never been measured. This lack of information motivated the present systematic program to study several of the observed species of transiron elements. In the present work, absolute single photoionization cross sections for Br$^{+}$ and Rb$^{3+}$ have been measured at the Advanced Light Source at Lawrence Berkeley National Laboratory using the mergedbeams technique. Both ions were measured from the metastable region to at least 10 eV above the direct ionization threshold. Rydberg resonance series are identified for each ion where possible. [Preview Abstract] 

K1.00156: InnerShell Photodetachment of Nickel Negative Ions Ileana Dumitriu, Rene Bilodeau, Daniel Gibson, Wes Walter, Thomas Gorczyca, Alex Aguilar, Daniel Rolles, Zoran Pesic, Nora Berrah Transition metals are of interest for their catalytic properties and participation of $d$orbital electrons in the bonding properties. Theoretical studies of transition metal negative ions are challenging due to strong electron correlation effects and existence of lowlying electronic states as a result of open $d$shell configurations. Experimental studies of transition metal negative ions are limited compared with the ions belonging to the main groups of periodic table and these studies have mostly investigated the valenceshell electrons using laser spectroscopy. Our experiment focuses on innershell photodetachment studies of Ni$^{}$ transition metal ions using the IonPhoton Beamline on the ALS beamline 10.0.1. Innershell photodetachment spectrum was recorded over a range of 30 to 90 eV which includes the 3$p$ threshold for Ni$^{}$. The highercharge state formation was also observed, indicating multielectron ejection processes. The absolute crosssection for the production of Ni$^{+}$ will also be presented. [Preview Abstract] 

K1.00157: ELECTRONMOLECULE COLLISIONS 

K1.00158: Study of Metastable N$_{2}$ Production Using an N$_{2}$ Matrix Detector William McConkey, Wladek Kedzierski, Cyrus Cerkauskas Metastable N$_{2}$ molecules produced in the interaction of electrons of carefully controlled energy with a thermal beam of N$_{2}$ in a crossed beam setup have been studied in the energy range from threshold to 400 eV. The ebeam is pulsed and the metastables produced drift to a solid nitrogen target held at 10 K. Here they form excimers which immediately radiate. The resultant photons are detected using a photomultiplierfilter combination. Timeofflight techniques are used to separate these photons from prompt photons produced in the initial electronN$_{2}$ collision. The excimer emission is strongest in the green but still significant in the red spectral region. Excitation functions will be presented together with threshold measurements. These help to identify the metastable states being observed and the excitation mechanisms which are responsible. [Preview Abstract] 

K1.00159: HeavyRydberg ionpair formation in Rydberg atom collisions: Probing dissociative electron attachment Michael Kelley, Sitti Buathong, F. Barry Dunning While electron transfer in Rydberg atom collisions with attaching targets forms a valuable technique with which to create heavyRydberg ion pairs to examine their properties, we demonstrate here that measurements of their velocity distributions can also provide insights into the behavior of the excited intermediates formed through initial electron transfer. The experimental results are analyzed with the aid of a Monte Carlo collision code that models the details of electron transfer reactions. Results for a variety of targets are presented that demonstrate the use of this approach to examine the dynamics of dissociative electron attachment, the lifetimes of the intermediates created, and the channels by which they decay. [Preview Abstract] 

K1.00160: Isomer and Fluorination Effects among Fluorine Substituted Hydrocarbon C$_{3}$/C$_{4}$ Molecules in Electron Impact Ionization U.R. Patel, K.N. Joshipura Electron collision processes are very important in both manmade and natural plasmas, for determining the energy balances and transport properties of electrons. Electron molecule scattering leading to ionization represents one of the most fundamental processes in collision physics. In the gas phase, the total efficiency of the process is described by the absolute total electron impact ionization cross section. Carbon based materials are some of the widely used materials for a divertor plate and magnetically confined fusion devices. In the ``ITER,'' it is very important for steady state operation to have an estimate of the lifetime of carbon plasma facing components. Apart from fusion plasma relevance, the present theoretical study is very important in modeling and controlling other electron assisted processes in many areas. Hydrocarbons play an important role for plasma diagnostics as impurities in the Tokamak fusion divertor, as seed gases for the production of radicals and ions in low temperature plasma processing. Fluorine substituted hydrocarbons (perfluorocarbons) are important as reactants in plasma assisted fabrication processes. In the present work, we have calculated total ionization cross sections $Q_{ion}$ for C$_{3}$/C$_{4}$ Hydrocarbon isomers by electron impact, and comparisons are made mutually to observe isomer effect. Comparisons are also made by substituting H atom by F atom and revealing fluorination effect. The present calculations are quite significant owing to the lack of experimental data, with just an isolated previous theoretical work in some cases. [Preview Abstract] 

K1.00161: Investigation of low frequency molecular Bremsstrahlung radiation from laser induced breakdown of air Prem Kiran Paturi, Vinoth Kumar Lakshminarayanan, Manikanta Elle, Leela Chelikani Low frequency electromagnetic radiation (301000 MHz), due to molecular Bremsstrahlung, from ns and ps laser induced breakdown (LIB) of atmospheric air is studied. In the plasma formed by the LIB of atmospheric air, interaction of charged particles with neutral clusters of atoms and molecules result in the emission of low frequency radiation. With increasing laser intensity, the plasma frequency ($\omega_{\mathrm{P}})$ comes closer to the laser frequency ($\omega_{\mathrm{L}})$, leading to higher degree of ionization. This is observed to reduce the electronneutral interactions decreasing the low frequency emissions. Thus the emissions from ps LIB are 23 orders smaller than those from ns LIB. While traversing from the loose to tight focusing conditions, the emissions from ns LIB and ps LIB were observed to be increasing and decreasing, respectively. This confirms the role of the number of seed electrons and their interaction with neutrals on the low frequency emissions. The emissions were observed to be spectral selective, dependent on the polarization state of the input laser pulses and the detecting antenna. [Preview Abstract] 

K1.00162: Would Dissociative Recombination of DNA$^{+}$ be a Possible Pathway of DNA Damage? H.C. Kwon, Z.P. Chen, R.A. Strom, V.M. Andrianarijaona It is known that dissociative recombination (DR) is one of the very efficient processes of destruction of molecular cations into neutral particles. During the past few years, the focus of DR has been expanded from small inorganic molecules to macromolecular cation [see for instance \textit{Phys. Chem. Chem. Phys.}, 2010,12, 1167011673]. We are probing the possibility of the DR of DNA$^{+}$ after ionization of DNA, for example due to ionizing radiation. Therefore we are investigating the existence of autoionization states within nucleotide bases (Guanine, Adenine, Cytosine, and Thymine). Our results from computational analysis using the modern electronic structure program ORCA will be presented. [Preview Abstract] 

K1.00163: Investigation of the Effects of Atomic Number and Constitution on ChirallySensitive ElectronInduced Molecular Breakup Joan Dreiling, Frank Lewis, Timothy Gay We present the results of our search for asymmetric interactions between longitudinally spinpolarized electrons and different chiral halocamphor molecules. We define the asymmetry as $A =$ [($I_{\uparrow }  I_{\downarrow })$/($I_{\uparrow } +I_{\downarrow })$]$_{L} $ [($I_{\uparrow }  I_{\downarrow })$/($I_{\uparrow } + I_{\downarrow })$]$_{R}$, where $I_{\uparrow }$ ($I_{\downarrow })$ is the current measured for spinup (spindown) electrons and the ``$L$'' and ``$R$'' subscripts correspond to the left and righthanded chirality of the molecules [1]. Two electronmolecule interaction channels were studied: electron transmission (related to the total scattering cross section) and dissociative electron attachment (DEA). Three halocamphor molecules were investigated: 3bromocamphor (C$_{\mathrm{10}}$H$_{\mathrm{15}}$BrO), 3iodocamphor (C$_{\mathrm{10}}$H$_{\mathrm{15}}$IO), and 10iodocamphor. While the transmission asymmetry data do not show a strong molecular dependence, the DEA asymmetries collected for bromocamphor and iodocamphor are qualitatively different, suggesting that the atomic number of the heaviest atom in the molecule plays a crucial role in the asymmetric interactions. The DEA asymmetry data for 3 and 10iodocamphor have the same qualitative behavior, but the 10iodocamphor asymmetry is about twice as large at the lowest energies investigated, so the location of the heavy atom in the camphor molecule also affects the asymmetries. [1] J.M. Dreiling and T.J. Gay, Phys. Rev. Lett. \textbf{113}, 118103 (2014). [Preview Abstract] 

K1.00164: Confinementcorrelation impact upon electron elastic scattering off endohedral atoms: the $e + {\rm Ne}@{\rm C}_{60}$ case Valeriy Dolmatov, Miron Amusia, Larissa Chernysheva A recent work [1] has provided the initial insight into electron elastic scattering off endohedral atoms $A@C_{60}$. There, the atom $A$ and $C_{60}$ cage were regraded as nonpolarizable targets. A question of how lifting the rigid$A$rigid$C_{60}$ constrain can affect $e + A@C_{60}$ scattering has remained open. The present study provides a partial insight into the problem. It accounts for polarization of the atom by incoming electrons in the presence of rigid $C_{60}$. This is an interesting in itself topic of study from the point of view of basic science. The Dyson theory for the selfenergy part of the Green function $\Sigma_{e}(\epsilon)$ of an electron moving in the field of A confined inside of rigid $C_{60}$ is employed in the study. The function $\Sigma_{e}(\epsilon)$ is regarded in the framework of the RPAE theory. The $e + Ne@C_{60}$ elastic scattering is chosen as a case study. The s, p, d, f, g, and h phase shifts and partial (and total) electron elasticscattering cross sections are calculated with and without accounting for $\Sigma_{e}(\epsilon)$. Calculated results provide the first insight into the confinementcorrelation impact upon $e+A@C_{60}$ elastic scattering.\\[4pt] [1] V. K. Dolmatov, M. B. Cooper, and M. E. Hunter, J. Phys. B \textbf{47}, 115002, 2014. [Preview Abstract] 

K1.00165: Revealing Dissociative Electron Attachment Dynamics in Polyatomic Molecules Using Momentum Imaging Experiments and Electron Scattering Calculations Ali Belkacem, Daniel Slaughter Understanding electrondriven chemical reactions is important for improving a variety of technological applications such as materials processing and the important role they play in the radiation damage in bulk matter. Furthermore, dissociative electron attachment often exhibits siteselective bond cleavage, which holds promise for prediction and precise control of electrondriven chemical reactions. Recent dynamical studies of these reactions have demonstrated that an understanding of anion dissociation dynamics beyond simple onedimensional models is crucial in interpreting the measured fragment angular distributions. We combine ion fragment momentum imaging experiments with electron attachment entrance amplitude calculations to interrogate the nonBornOppenheimer dynamics of dissociative electron attachment in polyatomic molecules. We will report recent experimental developments in molecules of technological interest including methanol, methane and uracil. [Preview Abstract] 

K1.00166: ATOMIC, MOLECULAR AND CHARGED PARTICLE COLLISIONS 

K1.00167: Single and Double Ionization in F$^{9+}$ + He Collisions M.S. Pindzola, T.G. Lee, J. Colgan Timedependent closecoupling methods are used to calculate differential cross sections for the single and double ionization in F$^{9+}$ + He collisions. Single ionization energy differential cross sections are compared with recent experimental results. Double ionization energy differential cross sections are presented to guide future experiments. [Preview Abstract] 

K1.00168: Relativistic regimes in which Compton scattering doubly differential cross sections obtained from impulse approximation are accurate due to cancelation of errors. L.A. LaJohn, R.H. Pratt There is no simple parameter that can be used to predict when impulse approximation (IA) can yield accurate Compton scattering doubly differential cross sections (DDCS) in relativistic regimes. When Z is low, a small value of the parameter \textless p\textgreater /q (where \textless p\textgreater is the average initial electron momentum and q is the momentum transfer) suffices. For small Z the photon electron kinematic contribution described in relativistic Smatrix (SM) theory reduces to an expression, X$^{rel}$, which is present in the relativistic impulse approximation (RIA) formula for Compton DDCS. When Z is high, the SMatrix photon electron kinematics no longer reduces to X$^{rel}$, and this along with the error characterized by the magnitude of \textless p\textgreater /q contribute to the RIA error $\Delta $. We demonstrate and illustrate in the form of contour plots that there are regimes of incident photon energy $\omega_{i}$ and scattering angle $\theta$ in which the two types of errors at least partially cancel. Our calculations show that when $\theta$ is about 65$^{\circ}$ for Uranium Kshell scattering, $\Delta $ is less than 1{\%} over an $\omega_{i}$ range of 300 to 900 keV. [Preview Abstract] 

K1.00169: Atomic Beam Density Characterization by Diode Laser Absorption Spectroscopy Paul Oxley, Joseph Wihbey Atomic beams are used in many atomic physics experiments, and one of the key parameters of the beam is its density. We present experimental and theoretical details of a technique to determine absolute lineintegrated beam densities based on resonant laser absorption. In our experiment a thermal lithium beam is chopped and a lockin amplifier detects the laser absorption signal at the chop frequency. This method is sensitive enough to allow detection of beams with densities as low as 5x10$^{\mathrm{5}}$ atoms/cc, for a 9mm beam thickness. We also explore the possibility of extending our method by using the related technique of wavelength modulation spectroscopy. This will reduce noise in the absorption signal, allow the beam density to be determined more rapidly, and will not require the atomic beam to be chopped. We anticipate improvements of up to a factor of 100 reduction in noise and up to a factor of 1000 increase in speed. [Preview Abstract] 

K1.00170: Tunable Catalysis of Water to Peroxide with Anionic, Cationic, and Neutral Atomic Au, Ag, Pd, Rh, and Os K. Suggs, F. Kiros, A. Tesfamichael, Z. Felfli, A.Z. Msezane Fundamental anionic, cationic, and neutral atomic metal predictions utilizing density functional theory calculations validate the recent discovery identifying the interplay between Regge resonances and RamsauerTownsend minima obtained through complex angular momentum analysis as the fundamental atomic mechanism underlying nanoscale catalysis. Here we investigate the optimization of the catalytic behavior of Au, Ag, Pd, Rh, and Os atomic systems via polarization effects and conclude that anionic atomic systems are optimal and therefore ideal for catalyzing the oxidation of water to peroxide, with anionic Os being the best candidate. The discovery that cationic systems increase the transition energy barrier in the synthesis of peroxide could be important as inhibitors in controlling and regulating catalysis. These findings usher in a fundamental and comprehensive atomic theoretical framework for the generation of tunable catalytic systems. The ultimate aim is to design giant atomic catalysts and sensors, in the context of the recently synthesized trimetal Ag@Au@Pt [1] and bimetal Ag@Au [2] nanoparticles for greatly enhanced plasmonic properties and improved chemical stability for chemical and biological sensing. \\[4pt] [1] N. Deogratias, M. Ji, Y. Zhang, J. Liu, J. Zhang and H. Zhu, \textit{Nano Res.} \textbf{8}(1), 271 (2015)\\[0pt] [2] Y. Yang, J. Liu, Z.W. Fu, and D. Qin, J. Am. Chem. Soc. \textbf{136}, 8153 (2014) [Preview Abstract] 

K1.00171: A Novel MicroMott Polarimeter with Cylindrical Symmetry Nathan Clayburn, Evan Brunkow, George Rutherford, Samantha Burtwistle, Timothy Gay A novel microMott polarimeter of cylindrical symmetry has been designed, constructed, and tested. It has a maximum efficiency at 10 keV of 5 x 10$^{4}$ when $\Delta $E $=$ 1300 eV. (We define $\Delta $E to be the maximum energy loss an electron scattering from the polarimeter's Au target can have suffered and still be detected [1].) At 20 keV, the maximum voltage we put on the Au target, the effective Sherman function (analyzing power) is 24{\%} at $\Delta $E $=$ 600 eV where the efficiency is 5 x 10$^{5}$. Below $\Delta $E of 500 eV at 20 keV, pollution from positive ions and xrays reduces the analyzing power. We present SIMION [2] simulations that explain qualitatively this latter result. \\[4pt] [1] T.J. Gay, J.A. Brand, J.E. Furst, M.A. Khakoo, W.V. Meyer, W.M.K.P. Wijayaratna, and F.B. Dunning, Rev. Sci. Instrum. 63, 114 (1992).\\[0pt] [2] SIMION{\textregistered} Version 8.1 [Preview Abstract] 

K1.00172: Optical control and spectroscopic studies of collisional population transfer in molecular electronic states Ergin Ahmed, Xinhua Pan, John Huennekens, Marjatta Lyyra Understanding the basic physics of collision processes between atoms and molecules is of fundamental importance for large number of areas of research including chemical reactivity, ultra cold atoms and molecules, and astrophysics of the interstellar medium. We have experimentally demonstrated [1] optical control of the singlet/triplet probability distribution in the outcome of collisions involving lithium dimer molecules and argon atoms. The control is achieved using the AutlerTownes (AT) effect to manipulate the spin character of a spinorbit coupled pair of levels serving as a ``gateway'' between the singlet and triplet electronic state manifolds. As a result we show that the rate coefficient of a collisional process between excited molecules ($^{7}$Li$_{2})$ and atoms (Ar) leading to internal quantum state changes in the molecules can be effectively manipulated with a laser. In addition, as an extension of these results new gateway levels can be created from singlet and triplet levels that hardly interact to begin with. \\[4pt] [1] E. H. Ahmed et al., \textit{Physical Review A} \textbf{89}, 061401(R) (2014). [Preview Abstract] 
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