Bulletin of the American Physical Society
38th Annual Meeting of the Division of Atomic, Molecular, and Optical Physics
Volume 52, Number 7
Tuesday–Saturday, June 5–9, 2007; Calgary, Alberta, Canada
Session K1: Poster Session II 
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Room: TELUS Convention Center Macleod A, 4:00pm  6:00pm 

K1.00001: QUANTUM INFORMATION; OPTICAL 

K1.00002: Decoherence of a driven quantum system interacting with environment through many degrees of freedom Zhongyuan Zhou, ShihI. Chu, Siyuan Han We present a comprehensive approach for the study of decoherence of an acfielddriven multilevel quantum system interacting with environment through many degrees of freedom. In this approach, the system is described by a reduced density operator and the environment is characterized by a number of spectral densities. The reduced density operator is governed by a master equation in which the effect of ac fields and leakage to noncomputational states are included. The approach is applied to investigate decoherence of a SQUID flux qubit with a twodimensional (2D) potential coupled to environment through its control and readout circuits. The calculated relaxation time agrees well with experimental result when the potential is quasi onedimensional (1D). Effects of the second degree of freedom, which is frozen in a quasi1D system, on relaxation and decoherence times are examined systematically by varying circuit parameters. [Preview Abstract] 

K1.00003: Efficient NMR manipulation of single electronnuclear spin registers Paola Cappellaro, Liang Jiang, Mikhail Lukin Motivated by recent experiments with single nitrogenvacancy centers in diamond, we consider a fewqubit quantum system composed of a single electron and proximal nuclear spins. Initialization and readout of such a quantum register is accomplished optically via the electron spin. Due to the large hyperfine coupling, the nuclear spins can be addressed individually. We describe NMRbased techniques for efficient initialization and coherent manipulation of such registers composed of multiple nuclear spins. We analyze feasible performances and practical limitations of this approach in a realistic setting. This hybrid approach combines ideas from quantum optics, mesoscopic physics and NMR to yield a robust, potentially scalable quantum information system. [Preview Abstract] 

K1.00004: Scalable Quantum Networks based on FewQubit Registers Liang Jiang, Jacob Taylor, Anders Sorensen, Mikhail Lukin We describe and analyze a hybrid approach to scalable quantum computation that is based on probabilistically connected optical network consisting of fewqubit quantum registers. We show that, in principle, twoqubit quantum registers, connected by probabilistic entanglement generation, suffice for scalable, deterministic quantum computation. We then show that with additional three qubits per register, robust nonlocal quantum operations can be implemented, even when state preparation, measurement, and entanglement generation all have limited fidelity. Finally, we discuss error thresholds relevant for scalability of our approach by mapping it to a general network error model. [Preview Abstract] 

K1.00005: Universal Control of Nuclear Spins via Anisotropic Hyperfine Interactions Jonathan S. Hodges, Jamie C. Yang, Chandrasekhar Ramanathan, David G. Cory Nuclear spins are appealing as qubits in quantum information processing given their long coherence times; however these systems still require an efficient means of initial state preparation and state measurement. Many proposals rely on a localized electron spin coupled to the nuclear spins via the hyperfine interaction for aiding in initialization and readout. When the hyperfine interaction between electron and nuclear spins has an anisotropic coupling, we describe how universal control over the combined subsystems can be attained by driving only the electron spin transitions. Building on the GRAPE \footnote{N. Khaneja et al., J. Magn. Reson. 172, 296 (2005)} method for quantum control, we propose a method for modulating solely the electron spin that allows for faster, more robust quantum operations on the nuclear spins than would be achieved by addressing the nuclear spins directly. We experimentally demonstrate these ideas in a test bed system of one S=1/2 electron spin and one I=1/2 nuclear spin and show that a universal set of gates can be achieved on this system. Also, we present preliminary results on our ability to polarize the combined system by controlling polarization transfer from the electron to the nuclear spin in the presence of electron spin relaxation. [Preview Abstract] 

K1.00006: Real Source Quantum Key Distribution Relays Gina Howard, Wolfgang Tittel, Barry C. Sanders We have developed a model for relaybased quantum key distribution that incorporates multiphoton source events and dark counts at detectors. The model compares achievable quantum key distribution rates for configurations with different numbers of segments over a range of distances. Different photon source distributions and dark count rates are compared for given configurations to ascertain the impact of the source and detector imperfections on secure key rates. [Preview Abstract] 

K1.00007: Towards Fast Quantum Secured Communication Itzel Lucio Martinez, Philip Chan, Steve Hosier, Xiaofan Mo, Wolfgang Tittel An ideal implementation of QKD would employ a perfect single photon source which is currently not available. The decoy state protocol uses faint laser pulses with different intensities that allows the two end points to eliminate cryptographic key data created from multiphoton pulses. The remaining cryptographic key data is obtained from singlephoton pulses making it absolutely secure. The decoy state protocol increases the distance of transmission and the rate of secret key generation. In this poster we discuss the implementation of a decoy state protocol using polarization encoding in a standard telecommunication fibre Alice generates laser pulses which are then intensity modulated and attenuated to produce either signal or decoy states. Alice then uses phase modulators to create polarization states which she sends, via a fibre link, to Bob. Bob uses polarization beam splitters and single photon detectors to separate and measure the polarization states. The implementation of the decoy state protocol and the advances in single photon detectors expected in the next few years, will result in a significant increase in the achievable raw key rate. It is thus necessary to develop high speed solutions for the classical postprocessing required for QKD. To this end, a FPGA implementation of lowdensity paritycheck codes utilizing a set of precomputed codes is being investigated. [Preview Abstract] 

K1.00008: Production of Entangled Photon Pairs in Optical Fiber via FourWave Mixing Joshua Slater, Ahdiyeh Delfan, Allison Rubenok, F\'elix Bussi\`eres, Nicolas Godbout, Wolfgang Tittel Building a quantum cryptography network with optical fiber is desirable as fiber is well understood and networks are already widespread. Transmitting through freespace is also desirable as it allows key distribution where optical fibers are not available. However, the absorption minima for these methods are at widely separated wavelengths: 1550 nm for fiber and around 800 nm for freespace. To create a hybrid network we are working towards teleporting quantum information from a photon suitable for fiber transmission to a photon suitable for freespace transmission. To achieve this, we require entangled photons at widely separated wavelengths, which are normally produced in nonlinear crystals. Our research focuses on producing the entangled pair directly in optical fiber using fourwave mixing (FWM). We examined the possibility of using two pump lasers at widely separated wavelengths, whereas previous FWM photon pair source experiments have used a single pump laser. We present initial results of phase matching for feasible experimental setups. [Preview Abstract] 

K1.00009: Manipulation of Energy Gap of Thallium Quantum Dots Choongyu Hwang, Namdong Kim, Geunsik Lee, Sunyoung Shin, Sanghun Uhm, Hyosang Kim, Jaesam Kim, Jinwook Chung We have characterized the electronic properties of thallium (Tl) quantum dot (QD) array using highresolution electronenergyloss spectroscopy, photoemission spectroscopy, and firstprinciple calculations. The surface with the QD's exhibits a weakly semiconducting character with a band gap less than 0.23 eV in sharp contrast with previous scanningtunneling spectroscopy observation [1]. We have observed the nonvarying excitation energy of an interband transition in conflict with two kinds of binding energy shift with the variation of effective separation between the QD's. We analyze the experimental findings through firstprinciple calculations based on the density functional theory using ab initio plane wave pseudopotential method within generalizedgradient approximations. Nine Tl atoms are found to form a QD occupying the attractive basin around the Si restatoms in the faulted half unit cell and the surface is semiconductor with an energy gap of 0.11 eV. The calculated band structure of Tl QD's shows the bonding origin of surface states, confirming our experimental results. The origin of the difference in binding energy shift of each electron state is the interaction between electrons only in QD's, leaving the electron states irrelative to QD's unshifted. [1] L. Vitali, M. G. Ramsey, and F. P. Netzer, Phys. Rev. Lett. 83, 316 (1999). [Preview Abstract] 

K1.00010: Discerning thermal properties of entanglement in qubit rings using nconcurrence Yuval Sanders, Hilary Carteret, Barry Sanders We show that nconcurrence is an excellent tool for discerning the entanglement properties of qubit networks (e.g. rings) and demonstrate multiple entanglement revivals as temperature increases. [Preview Abstract] 

K1.00011: Floquet formulation for the investigation of multiphoton quantum interference in a superconducting qubit driven by a strong field SangKil Son, ShihI Chu We present a Floquet investigation of multiphoton quantum interference in a strongly driven superconducting qubit. The procedure involves a transformation of a timedependent problem into an equivalent timeindependent infinitedimensional Floquet matrix eigenvalue problem. The results of a twolevel qubit system show quantum interference fringes around multiphoton resonance positions in agreement with the experimental results of Oliver et al., Science\ \textbf{310}, 1653 (2005). We further explore the interference patterns in terms of quasienergies and the resonance position shifts as the tunneling strength increased. The Floquet formulation promises a new and accurate approach for the investigation of quantum interference phenomenon in the qubits. [Preview Abstract] 

K1.00012: Analytical methods for design of surfaceelectrode ion traps J.H. Wesenberg, J.M. Amini, R.B. Blakestad, J. Britton, K.R. Brown, R.J. Epstein, J.P. Home, W.M. Itano, J.D. Jost, C. Langer, D. Leibfried, R. Ozeri, S. Seidelin, D.J. Wineland Surfaceelectrode ion traps\footnote{J. Chiaverini et al., Quantum Inf. Comput. 5, 419 (2005).}$^,$\footnote{S. Seidelin et al., Phys. Rev. Lett. 96, 253003 (2006).} are promising candidates for the large scale multizone ion traps which are required for large scale quantum information processing. Electrode design for surfaceelectrode traps is complicated by the low symmetry and the large exposed electrode area. We apply a simple method\footnote{M. H. Oliveira et al., Eur. J. Phys. 22, 31 (2001).} to obtain analytical expressions for the field of arbitrarily shaped surfaceelectrodes. The efficiency of this method compared to traditional boundary (BEM) or finite (FEM) element methods has allowed us to use numerical optimization techniques to help in the design of advanced trap structures, such as intersections and ion separation zones. Work supported by DTO and NIST. J.H.W. acknowledges support from the Danish Research Agency. [Preview Abstract] 

K1.00013: Quantum Simulation Circuits for Sparse Hamiltonians Nathan Wiebe, Barry Sanders In 1982, Feynman suggested a quantum computer would efficiently simulate quantum systems and illustrated this concept with Heisenberg chains (Int. J. Theor. Phys, 21, 467), which are difficult to solve on a classical computer. Recently, building upon the work of Aharonov and TaShma (Proc. 35th Annual ACM Symp. on Theory of Computing, 2029), Berry, Ahokas, Cleve, and Sanders (arxiv:quantph/0508139) developed an algorithm that simulates state evolution for generic sparse timeindependent Hamiltonians, which accounts for all resources and has a cost that is nearly linear in time. We present a quantum circuit protocol to implement this algorithm. Furthermore we discuss the adaptation of this scheme for a broad class of timedependent Hamiltonians. [Preview Abstract] 

K1.00014: Quantum Simulators, Spin Systems, and Trapped Ions Warren Lybarger, John Chiaverini, Rolando Somma, David Lizon, W. Robert Scarlett, Malcolm Boshier, Dana Berkeland Manyquantumspin systems cannot be efficiently simulated on classical computers as they require exponentially large resources. Yet many such systems can be simulated efficiently with quantum simulators (QS) that do not require universal control like quantum computers. Following the work of Porras and Cirac [Phys. Rev. Lett. 92, 2079011 (2004)] we discuss current experimental efforts at Los Alamos to implement a QS for Isinglike and Heisenberglike models with trapped ion qubit ``spins''. The states of the QS follow nearly the same equations of motion as the systems of interest, and unlike with real materials, the experimenter has the advantage of direct access to and control over the spins. We will discuss progress towards proofofprinciple investigations of twoion simulations in a singlewell trap, in which we use stateselective optical forces to induce ionion interactions. [Preview Abstract] 

K1.00015: Ion heating rates in scalable trap architectures for quantum computation R.J. Epstein, D. Leibfried, J.J. Bollinger, S. Seidelin, J.H. Wesenberg, N. Shiga, J.M. Amini, R.B. Blakestad, J. Britton, K.R. Brown, J.P. Home, W.M. Itano, J.D. Jost, E. Knill, C. Langer, R. Ozeri, D.J. Wineland We describe the characterization of several microfabricated ion trap architectures for quantum computation. Our apparatus for testing planar ion trap chips\footnote{S. Seidelin \emph{et al.}, Phys. Rev. Lett. \textbf{96}, 253003 (2006).}$^,$\footnote{ J. Kim \emph{et al.}, Quantum Inf. Comput. \textbf{5}, 515 (2005).} features: a standardized chip carrier for ease of interchanging traps, a singlelaser Raman sidebandcooling scheme, and photoionization loading of Mg$^+$ ions. We measure the heating rate of an ion$^,$s motional degreeoffreedom, a factor which limits multiion logic gate fidelities. Two measurement techniques are compared, the standard Raman sideband technique and timeresolved fluorescence detection during Doppler recooling$^4$. One of the traps, fabricated from gold on fused silica, shows heating rates below 1 quanta/ms (motional frequency = 5.3 MHz), boding well for planar ion trap designs. [Preview Abstract] 

K1.00016: A Computational Comparison of Ion Heating Rates in Conventional and Rotating rfElectric Quadrupole Ion Traps Michael Cummings, Phillip Ashby, Robert Thompson Two distinct field geometries are of interest for the containment of ions in linear rfelectric quadrupole ion traps: the conventional (or flapping) and the rotating forms of the trapping fields [1]. Although much theoretical and experimental work has been devoted to the multiion dynamics in conventional ion traps, only the single particle motion in the rotating geometry has been explored in any detail. Here, we present a computational study of the many particle dynamics for both trap geometries, focusing on the temperature dependent heating rates. A wide range of particle numbers and stability parameters ($q$ values) are sampled, allowing for a detailed comparison of the thermal character of both traps. Additionally, the computational data are compared with the instability heating theory [2] and theoretical rfheating rate calculations. \\[1mm] [1] T. Hasegawa and J. J. Bollinger, Phys. Rev. A \textbf{72}, 043403 (2005). \\[1mm] [2] T. J. Harmon, N. MoazzanAhmadi, and R. I. Thompson, Phys. Rev. A \textbf{67}, 013415 (2003). [Preview Abstract] 

K1.00017: Multilayer Interconnects for Microfabricated Surface Electrode Ion Traps Jason Amini, Signe Seidelin, Janus Wesenberg, Joe Britton, Brad Blakestad, Kenton Brown, Ryan Epstein, Jonathan Home, John Jost, Chris Langer, Dietrich Leibfried, Roee Ozeri, David Wineland Microfabricated surface electrode traps for ions are a promising technology for building scalable trapping geometries for quantum information processing. We have expanded upon our single layer goldonfusedsilica surface electrode trap [1] to include a second patterned conducting layer under the trapping electrodes and have demonstrated the fabrication of this architecture using standard microfabrication techniques. The multilayer approach allows for a significant increase in multizone trapping complexity and permits improved trapping structures that are otherwise unattainable in single layer designs without vertical interconnects through the wafer. Using improved calculational methods [2], we are in the process of optimizing the planar designs to create modular elements that can be joined into larger multizone trapping structures. Work supported by DTO and NIST. 1. S. Seidelin \textit{et al.}, Phys. Rev. Lett. \textbf{96}, 253003 (2006). Also, see the abstract by S. Seidelin. 2. See the abstract by J. H. Wesenberg. [Preview Abstract] 

K1.00018: Quantum projection noise and squeezing with ions in a PenningMalmberg trap. N. Shiga, W.M. Itano, J.J. Bollinger We summarize initial progress towards making spin squeezed states with $\sim$100 $^{9}$Be$^{+}$ ions in a PenningMalmberg trap. We use the groundstate electron spinflip transition, which in the 4.5 T trap magnetic field has a 124 GHz transition frequency, as the ion qubit. With a 30 mW Gunn diode oscillator we have observed $\pi$times as short as 100 $\mu$s. We have realized projection noise limited spectroscopy\footnote{W.M. Itano, et al., Phys. Rev. A{\bf 47}, 3554 (1993).} on this transition, which is a prerequisite for demonstrating spin squeezing. For entangling the ions we plan to use a generalization of the few ion qubit phase gate developed at NIST\footnote{D. Leibfried, et al., Nature {\bf 438}, 639 (2005).} to generate an $\exp{(i\chi {J_{z}}^2 t)}$ interaction between all of the ion qubits. This interaction can be implemented on a single plane of ions\footnote{T.B. Mitchell, et al., Science {\bf 282}, 1290 (1998).} with a motional sideband, stimulated Raman transition. We have observed fast ($\sim$1 ms) magnetic field fluctuations of our magnet through spinecho spectroscopy. These fluctuations limit the amount of time that can be used to apply the squeezing. [Preview Abstract] 

K1.00019: Motional Narrowing of Optically Detected Single Nuclear Spin Qubit Liang Jiang, M.V. Gurudev Dutt, Lily Childress, Emre Togan, Mikhail Lukin We study quantum dynamics of individual nuclear spin qubit coupled to optically excited, proximal single electron spin. We show that nuclear spin dephasing can be very slow, even under conditions of fast optical excitation. We present a detailed theoretical model for this process, which is related to motional narrowing in NMR as well as quantum Zeno effect. These results are compared with detailed experimental study of single nuclear spins associated with~nitrogenvacancy centers in diamond. Finally, we discuss the relevance of these results to realization of~quantum information processing. [Preview Abstract] 

K1.00020: Quantum register based on individual electronic and nuclear spin qubits in diamond Emre Togan, M. V. Gurudev Dutt, Lily Childress, Liang Jiang, Jeronimo Maze, Fedor Jelezko, Philip Hemmer, Mikhail Lukin We describe a technique that makes use of coherent manipulation of an individual electron spin and individual nuclear spins in its environment to create a controllable quantum register composed of a few quantum bits (qubits). Using optical and microwave radiation to control an electron spin associated with the NitrogenVacancy (NV) color center in diamond, we demonstrate robust initialization of a twoqubit register at room temperature and transfer of arbitrary quantum states between electron and nuclear spin qubits. We further show that nuclear spin qubits can be well isolated from the electron spin, even during optical polarization and measurement of the electronic state. Finally, we observe coherent interactions between individual nuclear spin qubits, and demonstrate that they have excellent coherence properties. These registers can be used as a basis for scalable, optically coupled quantum information systems. [Preview Abstract] 

K1.00021: Coherence properties of individual electron and nuclear spins in diamond Jeronimo Maze, Lilian Childress, Gurudev Dutt, Liang Jiang, Mikhail Lukin, Emre Togan, Jacob Taylor, Philip Hemmer, Fedor Jelezko Understanding decoherence processes is essential for coherent manipulation of quantum bits. We consider the electron and nuclear spin associated with the negatively charged NV center in diamond, and show that their decoherence properties are governed by interactions with a spin bath composed of naturally occurring $^{13}$C isotopic impurities. This spin bath model yields estimates for coherences times $T_2$ which are in good agreement with experimental data, and reproduce the observed dependence of $T_2$ on the magnetic field. Physically, these results arise because the electron spin alters the properties of the nuclear spin bath, affecting both the coupling between $^{13}$C nuclei and their effective $g$ tensor. Detailed knowledge of this mechanism may be used to improved techniques for manipulating both electronic and single nuclear spins. [Preview Abstract] 

K1.00022: Noiseinduced Decoherence of Stark Wavepackets Studied Using an Echo Technique Wei Zhao, Jeffrey Mestayer, Jim Lancaster, F. Barry Dunning, Shuhei Yoshida, Carlos Reinhold, Joachim Burgdorfer The decoherence of high$n $Stark wavepackets induced by noise is examined using a quantum beat echo technique. Noise, i.e., coupling to the environment, causes irreversible dephasing of the wavepacket and reduces the amplitude of the echoes. Here we apply synthesized noise to Stark wavepackets and quantify their robustness against decoherence by measuring the size of the echoes. The wavepackets are produced by sudden application of a transverse dc field to quasionedimensional n=350 Rydberg atoms. Their subsequent evolution is monitored using a halfcycle probe pulse. The technique can be applied on timescales much shorter than those associated with revivals allowing measurement of decoherence times even in the presence of very strong dephasing. [Preview Abstract] 

K1.00023: Cascaded emission from cold atomic ensembles HsiangHua Jen, Stewart Jenkins, Alex Kuzmich, Brian Kennedy We study the phase matched twophoton cascade emission from a collection of cold alkali atoms induced by two color laser excitation. The cascade configuration, which has recently been employed for the generation of polarizationentangled photon pairs at infrared and telecommunication wavelengths Chaneliere et al. [PRL 96, 093604 (2006) ], exhibits superradiant time scales for the infrared field component. We will present a theoretical analysis which explain the characteristic features observed. [Preview Abstract] 

K1.00024: Control of single neutral atoms for quantum information Michael Gibbons, Soo Kim, Kevin Fortier, Peyman Ahmadi, Michael Chapman Experimentally, optical traps have suffered for many years from unexplained heating rates. These have limited the trap lifetime to an order of magnitude less than expected for the vacuum ranges attainable. Recently, we have achieved very long lifetimes of single rubidium atoms trapped in a 1D optical lattice ($\lambda $=1064 nm) by optical molasses cooling. We have transported the laser cooled atoms, trapped in an optical lattice, to a high finesse cavity. Such long lived neutral atoms are of particular interest for quantum information storage and processing schemes. [Preview Abstract] 

K1.00025: Entangling Neutral Atoms with SymmetrizationDependent Dynamics Nathan Babcock, Ren\'e Stock, Mark Raizen, Barry Sanders Trapped neutral atoms provide a promising medium in which to perform quantum computations since they have long decoherence times and can easily be interfaced with light for singlequbit operations and measurements. Despite these advantages, reliable methods for entangling and transporting atomic qubits must be devised before practical atomic quantum information processing devices can be realized. We propose a method for entangling a pair of indistinguishable neutral atoms stored in separated optical dipole traps. We model this trapping potential in one dimension as a pair of Gaussian wells that can be brought together for atoms to interact. The dynamics of this process depend on the symmetrization parameters of the initial state, and by choosing the correct interaction time a controlledphase gate can be designed. Adiabatic separation guarantees that the atoms end up in opposite traps. We provide both adiabatic and timedependent numerical simulations of the entangling process. Additionally, we consider a novel method for creating entangled qubits via selective excitation of atoms in such optical dipole traps. [Preview Abstract] 

K1.00026: REACTIVE AND HEAVYPARTICLE COLLISIONS 

K1.00027: L SubShell Cross Sections measured for 75300 keV protons on Selected RareEarth Elements. Sam J. Cipolla L subshell xray production cross sections were measured for 75300 keV proton impact on thick elemental targets ranging from Gd through Yb. Xray yields were measured using a highresolution Si(Li) detector with an ultrathin window. The results were compared with ECPSSR theory with and without the unitedatom approximation for the bindingenergy effect and the relativistic correction. Multiple ionization effects are also taken into account. [Preview Abstract] 

K1.00028: Signature of Target Excitation In Nitrogen Fragmentation C.P. Safvan, Jyoti Rajput, Sankar De, A. Roy Target excitation following ionimpact has been observed to play a significant role in multielectron capture studies in ionatom collision experiments. Probably this is the first report on the role of target excitation in ioninduced fragmentation of nitrogen [1]. The multiple ionization and fragmentation of N$_{2}$ by ion impact is studied using position sensitive TOF technique in multihit coincidence mode in the LEIBF laboratory of IUAC, India. With Ar$^{9+}$ projectiles at a velocity of 1 a. u., we observe a total of seven fragmentation channels originating from multiply charged transient molecular ions. The kinetic energy release (KER) spectra of all the observed fragmentation pathways were extracted from the analyzed data on an event by event basis. \textit{Ab initio} calculations were done for determining the potential energy curves for multiply charged nitrogen molecular ions to account for the observed KER using the quantum chemistry package GAMESS. The preference of symmetric charge breakup channels over the asymmetric ones is clearly observed. A signature of core excitation of the target molecule followed by Auger emission is observed in the kinetic energy spectra of the N$^{3+}$N$^{3+}$ fragmentation channel in the form of a clear distinct peak at 72 eV [1], this value being very close to the most probable KER in the case of N$^{2+}$N$^{3+ }$fragmentation channel. Ref: [1] Jyoti Rajput et. al., PRA, 74, 032701 (2006) [Preview Abstract] 

K1.00029: Electronimpact excitation of dihydrogen sulfide in the VUV spectral region. Eric Vyskocil, Stephen Brotton, Wladyslaw Kedzierski, William McConkey The electronimpact excitation of dihydrogen sulfide and discharged fragments including atomic sulfur is presented in the VUV spectral range from 90 nm  150 nm. Hydrogen sulfide gas was dissociated by a microwave discharge tube prior to injection into an interaction region where electronimpact excitation occurred. By comparing the discharge `on' and discharge `off' spectra, contributions to the spectra from dissociative excitation of the parent molecule and from direct excitation of the discharged fragments could be determined. Excitation functions for the different spectral features were determined for electron energies from threshold to 200 eV. [Preview Abstract] 

K1.00030: Vibrationallyresolved Charge Transfer for Proton Collisions with CO ChihYuan Lin, Phillip Stancil, Y. Li, J.P. Gu, H.P. Liebermann, Robert Buenker, Mineo Kimura Electron capture by protons following collisions with carbon monoxide, and the reverse process, is studied with a quantal molecularorbital coupledchannel method utilizing the infinite order sudden approximation for collision energies between 0.5 and 1000 eV/u. The potential surfaces and couplings, computed with the multireference single and doubleexcitation (MRDCI) method for a range of H$^{+}$CO orientation angles and CO separations, are adopted in the scattering calculations. Results including vibrationallyresolved and orientationangle dependent cross sections are presented for a range of CO and CO$^{+}$ vibrational levels. Comparison with experiment is made where possible and the relevance of the reaction in astrophysics and atmospheric physics is discussed. [Preview Abstract] 

K1.00031: Geometric and Isotopic Influences on the Fragmentation Patterns of Rapidly Ionized Methane and Ammonia Laura Doshier, Amy Lueking, Ivan Lee, Eric Wells, Eli Parke, Mat Leonard, Kevin D. Carnes, Itzik BenItzhak The fragmentation branching ratios of (deuterated) ammonia and methane ionized by 19 MeV F$^{7+}$ and 4 MeV H$^{+}$ projectiles have been measured with an emphasis on dissociation channels that require bond rearrangement. For these projectiles, the collision time is approximately 10 attoseconds, a duration over which nuclear motion is negligible. As a result, the rearrangement occurs during the postcollision dissociation process and nuclear mass plays a role. Production of H$_{2}^{+}$ and H$_{3}^{+}$ ions, in coincidence with either neutral or ionic fragments, was analyzed for these eight collision systems. Statistically significant isotopic effects are observed in some ($e.g.$ H$^{+}$ + NH$_{3}^{+} \quad \to $ H$^{+}$ + N + H$_{3}^{+}$ ), but not all ($e.g$. F$^{7+}$ + NH$_{3}^{+} \quad \to $ F$^{7+}$ + N + H$_{3}^{+})$, dissociation pathways. [Preview Abstract] 

K1.00032: Soft Xray Line Emission Spectra from HighlyCharged Solar Wind Ions on Cometary Gases: N$^{5,6+}$ on CO Winthrop Smith, Kenneth Miller, Christopher Verzani, Wesley Gohn, Quentin Kessel, Steven J. Smith, Ara Chutjian Laboratory measurements to benchmark space observations of x rays from comets approaching the sun were made using the highly charged ionbeam facility at JPL and the UConn 1 m grazing incidence CCD spectrometer. Beamgas spectra are obtained from ions found in the solar wind on CO and other cometary gases. We compare our latest measurements of line emission in the range 2 70 nm (~17600 eV) for N$^{5,6+}$, near the fast solar wind velocity (~700 km/s), with previous measurements involving the isoelectronic ions O$^{6,7+}$. The highest n states excited on the projectiles by single electron charge transfer agree approximately with the Coulomb overthebarrier model (e.g. for N$^{6+}$ on CO, primary excitation is mainly to n=4 and some to n=5 levels). The final ldependences are also under study. [Preview Abstract] 

K1.00033: Collision induced dissociation and dissociative capture of slow (keV) H$_{2}^{+}$ and HD$^{+}$ on atomic targets Nora G. Johnson, A. Max Sayler, Leah Van Nahmen, Sam Fahrenholtz, Eli Parke, D. Hathiramani, J.W. Maseberg, K.D. Carnes, I. BenItzhak Collision induced dissociation [CID, e.g. H$_{2}^{+}$ + Ar (He) $\to $ H$^{+ }$+ H + Ar (He)] and dissociative capture [DC, e.g. H$_{2}^{+}$ + Ar (He) $\to $ H$^{ }$+ H + Ar$^{+ }$(He$^{+})$] are measured and separated by 3D momentum imaging of the fragments. CID is further separated into two mechanisms: electronic (eCID) and vibrational (vCID) excitation, distinguished by the kinetic energy release and the momentum transfer to the center of mass of the projectile. Similarly, DC is separated into capture directly to the repulsive b$^{3}\Sigma _{u}^{+}$ state and predissociating c$^{3}\Pi _{u}$ state. Angular studies for both channels show vCID strongly prefers to be aligned perpendicularly to the beam direction whereas DC prefers parallel alignment. Our eCID data agrees nicely with theory [1]. [1] Green and Peek, Phys. Rev. \textbf{183}, 166 (1969). [Preview Abstract] 

K1.00034: Study of gasphase chemistry in a hotwire chemical vapor deposition reactor with trimethylsilane and hexamethyldisilane Brett Eustergerling, Xinmao Li, Yujun Shi Gasphase chemistry involved in the decomposition of trimethylsilane and hexamethyldisilane (HMDS) on a hot tungsten filament and the secondary gasphase reactions in a HWCVD reactor has been studied using vacuum ultraviolet laser single photon ionization in tandem with TOFMS. On the hot W filament, trimethylsilane is decomposed into (CH$_{3})_{2}$HSi and CH$_{3}$ radicals and HMDS is decomposed into (CH$_{3})_{5}$Si$_{2}$, CH$_{3}$, and (CH$_{3})_{3}$Si radicals. Biradical combination reactions among primary radicals and those later formed are found to be the main gasphase reaction pathways in the reactor for both precursors. Characteristic reactions of trimethylsilane are those with (CH$_{3})_{2}$HSi and (CH$_{3})_{2}$HSiCH$_{2}$ radicals directly or indirectly involved, resulting in the formation of peaks at m/z = 88, 118, 132, 146, 116 and 130. With relatively heavier radicals generated from the decomposition of HMDS, the characteristic reactions for HMDS are believed to be those producing peaks in higher mass region, such as peaks at m/z = 204, 218, 262, 276, and 290. [Preview Abstract] 

K1.00035: Spectral Hole Burning in the Dielectronic Recombination from a Continuum of Finite Bandwidth Edward Shuman, Wei Yang, Tom Gallagher The presence of an electric field converts the intermediate autoionizing Rydberg $n\ell$ states, through which dielectronic recombination passes, into $nk$ Stark states, which have autoionization and capture rates in excess of the radiative decay rates and contribute to dielectronic recombination. In zero field the high $\ell$ states do not contribute to dielectronic recombination, but the conversion to Stark states makes it possible and raises the dielectronic recombination rate. However, an electric field can also result in coupling to loss channels which locally reduce the dielectronic recombination rate. We have observed holes in the spectrum of dielectronic recombination from the Ba $6p_{3/2}8g$ continuum of finite bandwidth via the intermediate $6p_{1/2}ng$ states. The holes appear when an electric field is applied, and we attribute them to interaction with rapidly decaying $6p_{3/2}8\ell$ states, which diverts flux from dielectronic recombination. [Preview Abstract] 

K1.00036: Dielectronic Recombination Studies Motivated by Active Galactic Nuclei D.V. Lukic, D.W. Savin, M. Schnell, C. Brandau, D. Bernhardt, A. Mueller, S. Schippers, E.W. Schmidt, D. Yu, M. Grieser, J. Hoffmann, M. Lestinsky, D.A. Orlov, R. Repnow, F. Sprenger, A. Wolf, Z. Altun, N.R. Badnell Recent Xray satellite observations of active galactic nuclei indicate shortcomings in the low temperature dielectronic recombination (DR) data for iron Mshell ions. In order to resolve this issue and provide reliable iron Mshell DR data, we are carrying out a series of measurements using the heavyion Test Storage Ring at the MaxPlanckInstitute for Nuclear Physics in Heidelberg, Germany. At temperatures where these ions are predicted to form in photoionized gas, we find significant discrepancies between our experimental results and previously recommended DR data. We are using our laboratory results to produce DR rate coefficients [1] and to benchmark our stateoftheart DR calculations [2]. Here we report on recent progress. [1] E. W. Schmidt et al., Astrophys. J., 641, L157 (2006) [2] N. R. Badnell, J. Phys. B, 39, 4285 (2006) [Preview Abstract] 

K1.00037: Sinusoidal Regge Oscillations from Short Lived Resonances D. Sokolovski, Z. Felfli, A.Z. Msezane It is well known that a resonance with a large angular life can produce sharp BreitWigner peaks in the energy dependence of integral cross sections [1,2]. Here we show that a shortlived resonance whose angular life is of order of one full rotation may produce a different kind of contribution to the integral cross section. This contribution has a sinousoidal form and its frequency is determined by the rotational constant of the complex. As one of the examples, we analyze the Regge oscillations observed in numerical simulations of the $F+H_2(v=0,j=0,\Omega =0) \rightarrow FH(v'=2,j'=0,\Omega'=0) + H$ reaction. In particular, we show that these oscillations are produced by two overlapping resonances located near the transition state and the van der Waals well, respectively [3]. \newline \newline [1] J. H. Macek, {\it et al.}, Phys. Rev. Lett., {\bf 93}, 183202, (2004). \newline [2] Z. Felfli {\it et al.}, J. Phys. B {\bf 39}, L353 (2006) \newline [3] D. Sokolovski, D. De Fazio, S. Cavalli and V. Aquilanti, J. Chem. Phys. (2007) (submitted). [Preview Abstract] 

K1.00038: Dielectronic recombination in highly charged ions to explore correlated highfield fewelectron dynamics and QED effects Z. Harman, V. Maeckel, A.J. Gonzalez Martinez, J.R. Crespo LopezUrrutia, U.D. Jentschura, C.H. Keitel, H. Tawara, J. Ullrich, A.N. Artemyev, I.I. Tupitsyn The study of dielectronic recombination with highly charged fewelectron ions provides unique possibilities for investigating correlation and QED effects in manyelectron systems as well as for exploring the relativistic dynamics of recombination processes. We calculated resonance energies and cross sections for KLL recombination channels into highlycharged Fe, Kr, Xe, Ba, W, and Hg ions [1], applying the multiconfiguration DiracFock and the configuration interaction DiracFockSturmian methods, and quantum electrodynamic manybody theory with additional screened QED corrections. Stateselected recombination spectra for these He to Blike ions have been recorded with the Heidelberg electron beam ion trap [2]. A comparison of theory and experiment shows a good overall agreement. However, a few interesting discrepancies are found in specific recombination resonances for initially Li and Belike Hg ions, suggesting the need for further studies. [1] Z. Harman {\it et al.}, Phys. Rev. A 73, 052710 (2006); [2] A.J. Gonz\'{a}lez Mart\'{\i}nez {\it et al.}, Phys. Rev. A 73, 052711 (2006) and V. M\"{a}ckel, master thesis, University of Heidelberg (2006) [Preview Abstract] 

K1.00039: Numerical calculation of supercritical Dirac resonance parameters by analytic continuation Edward Ackad, Marko Horbatsch The spectrum of the Dirac equation for hydrogenlike systems with extended nuclei becomes complicated when the nuclear charge exceeds a critical value $Z\approx 170$, since the lowest bound state becomes a resonance in the negative energy continuum. We address the problem of computing the resonance parameters by extending the mapped Fourier grid method to incorporate either complex scaling (CS) of the radial coordinate, or alternatively a complex absorbing potential (CAP). The method is tested on the case of quasimolecular UraniumCalifornium collisions in the monopole approximation. The method of CAP is found to be more stable than CS [1]. The decay widths $\Gamma(1S\sigma_{1/2})$ are obtained to higher precision than previously reported in the literature [2]. Current results for multichannel calculations will also be presented. \\ \noindent [1] E.Ackad and M. Horbatsch Phys. Rev. A 75 (2007) in press \\ \noindent [2] J. Reinhardt, B. M\"uller, W. Greiner Phys. Rev. A 24 103 (1981) [Preview Abstract] 

K1.00040: Differential cross section ratios for p + He collisions Michael Schulz, Ahmad Hasan, Tibor Vajnai, Miroslav Zapukhlyak, Tom Kirchner We have measured differential cross sections for single capture, double capture, and transfer excitation in p + He collisions. In the double to single capture cross section ratios R$_{DC}$ we observe peak structures around 0.5 to 1.0 mrad similar to those reported previously for the double to single ionization and transferionization to single capture ratios R$_{DI}$ and R$_{TI}$, respectively. However, surprisingly in our data for R$_{DC}$ the relative importance of these peaks maximize at a relatively small projectile energy of about 50 to 75 keV while in R$_{DI}$ and R$_{TI}$ the structures become increasingly pronounced with increasing projectile energy and are not observed below approximately 200 keV. We also found a pronounced peak structure in the double ratio R =R$_{TE}$/R$_{DE}$, where R$_{TE}$ is the transfer excitation to single capture ratio and R$_{DE}$ the double to single excitation ratio$^{1}$. Our theoretical calculation qualitatively reproduces the peak structure in R if the elastic scattering between the projectile and the residual target ion is treated quantummechanically. Finally, we revisited doubly differential single ionization data reported earlier$^{2}$ and found peak structures in the ratios between cross sections for different electron energies. $^{1}$W. Htwe et al., PRL \underline {73}, 1348 (1994) $^{2}$ T. Vajnai et al., PRL \underline {74}, 3588 (1995) [Preview Abstract] 

K1.00041: Electron Transfer, Excitation, and Ionization in Collisions between {\boldmath $\alpha$} Particles and H(1s) Atoms Thomas Winter Cross sections have been determined for electron transfer and excitation to each individual state up to 3d, to all states, and for ionization in 32400 keV $\alpha$H collisions using a doublecenter, 80281state Sturmian basis, substantially expanding the Sturmian calculations carried out a quarter of a century ago, which were limited to 1924 states and reported only electron transfer to all states, and only for a much more limitted energy range.\footnote{T. G. Winter, Phys. Rev. A {\bf 25}, 697 (1982).} At the lower and intermediate energies, cross sections have now been obtained with a basis of approximately the same number of Sturmians on each nuclear center, while at $\alpha$ energies of at least 800 keV results they have also been obtained with a predominantly targetcentered basis. The results for capture are better converged at the lower energies, while those for excitation and ionization, at the higher energies, where they may also be compared to Born results. Except at low energies, results may be compared with the atomic pluspseudostate results of Kuang and Lin,\footnote{J. Kuang and C. D. Lin, J. Phys. B {\bf 30}, 101 (1997)} while at all energies, the results for total capture and ionization may be compared with the coupledGaussian results of Toshima.\footnote {N. Toshima, Phys. Rev. A {\bf 50}, 3940 (1994).} [Preview Abstract] 

K1.00042: Time ordering in atomic collisions J.H. McGuire, A.L. Godunov, Kh Kh Shakov, L. Kaplan, A. Burin, D. Uskov Time ordering constrains interactions to occur in increasing (or decreasing) order. This places a constraint on the time evolution of the system and can lead to correlations in time of different particles in a few/many body system. Unlike overall time reversal, time ordering is not a conserved symmetry of the atomic system. A number of examples of observable effects of time ordering are presented. A convenient way to describe time ordering is to define the limit of no time ordering by replacing the instantaneous interaction by its time average. This is similar to the way in which spatial correlation is defined. Like spatial correlation, time ordering is usually formulated in the interaction representation. The effects of time ordering can differ in different representations. In energy space, conjugate to time space, time ordering is imposed as the $i \epsilon$ term in the Greens' function that corresponds to an initial condition (usually incoming plane waves and outgoing scattered waves). This permits offenergyshell (energy non conserving) fluctuations during the collision consistent with the Uncertainty Principle. [Preview Abstract] 

K1.00043: Development and Construction of a Novel Apparatus for Studying AnionNeutral Reactions. B. Seredyuk, H. Bruhns, H. Kreckel, W. Mitthumsiri, D.W. Savin, M.E. Bannister, C.C. Havener, A. Dorn, O. Heber, M.L. Rappaport, A.M. Covington We are developing a novel apparatus at the Columbia Astrophysics Laboratory to study anionneutral reactions. We will use fast, merged anionneutral beams and detect the charged end products. Laboratory beam energies will be in the keV range. Because the beams run colinear, centerofmass energies from the subeV to keV range can be achieved. Proofofprinciple measurements will be carried out using the associative detachment reaction ${\mathrm H}^ + {\mathrm H} \to {\mathrm H}_2^ \to {\mathrm H} _2 + {\mathrm e}^$. Published values for this process differ by over a factor of 5. Our proposed research will help to resolve this fundamental issue. We will present our current progress on the design and construction of this apparatus. Future possible research directions include adding a cold molecular anion source in order to study reactions of the type such as ${\mathrm X} + {\mathrm Y} {\mathrm Z}^$. This will allow investigations into a wide range of anionneutral reactions. [Preview Abstract] 

K1.00044: Theoretical Calculations for TransferExcitation and TransferIonization A.L. Harris, J.L. Peacher, M. Schulz, D.H. Madison Theoretical fully differential cross sections (FDCS) will be compared with experimental results for transferexcitation and transferionization occurring in protonhelium collisions. In the experiments, the incident proton captures one electron from a helium atom, and the remaining electron is left either in an excited bound state of the helium ion, or is ejected into the continuum as a free particle. The transferexcitation experiments have been performed in Rolla, MO and the transferionization experiments have been performed in Frankfurt, Germany. The theoretical approach we use is a full fourbody approach, taking each particle into account. This results in a nine dimensional integral to evaluate the Tmatrix. For transferexcitation, the incident projectile and the outgoing hydrogen atom are treated as HartreeFock distorted waves, and a Hylleraas wavefunction is used for the initial state helium atom. In the final state, bound hydrogenic wavefunctions are used for the hydrogen atom and the residual ion. In the case of transferionization, the ejected electron is treated as a HartreeFock distorted wave instead of a bound hydrogenic. [Preview Abstract] 

K1.00045: A Subnanosecond Ion Source for $\mu $mfocused Ion Beams C. H\"ohr, D. Fischer, R. Moshammer, A. Dorn, J. Ullrich A new, compact design of an ion source delivers nspulsed ion beams with low emittance, which can be focused to $\mu $m size. By using a highpower femtosecond (25 fs) laser pulse focused into a 10$^{6}$ mbar region, ions at very low temperatures are produced in the small focal volume (5 $\mu $m diameter by 20 $\mu $m length) through the simultaneous absorption of a high number of infrared photons. These ions are born in a cold environment and not in a hot plasma, and consequently have temperatures well below 10 K. The generated ion pulse (up to several thousand ions per bunch) is extracted from the source volume with ion optics that have been carefully tailored through simulations. Externally triggered, its subnanosecond duration and even smaller time jitter allows it to be superimposed with other pulses. [Preview Abstract] 

K1.00046: Electron Capture by B$^{5+}$ from H$_{2}$ At E $<$ 1.0 keV/amu Dwayne C. Joseph, Bidhan C. Saha The capture of electrons from molecular targets has considerable influence on the charge state balance of astrophysical as well as magnetically confined fusion plasmas. Molecular targets are in general more complicated than their atomic counterparts. A suitable method by freezing the molecular details of the targets is applied with a core potential [1] that represents the ionic core of the target. The molecular orbital method, including the electron translation factor [2], in the impact parameter formalism [3] is employed to evaluate the state selective cross sections. The motion of the nuclei is treated classically and that due to electron is considered quantum mechanically [4]. Details will be presented at the conference. [1] J. N. Bradsley, \textit{Case Stud. At. Phys}. \textbf{4}, 299 (1974). [2] M. Kimura and N. F. Lane, \textit{Adv. At. Mol. Opt. Phys}. \textbf{26}, 79 (1990). [3] B. C. Saha and A. Kumar, \textit{J. Mol. Struct. THEOCHEM}, \textbf{487}, 11 (1999). [4] A. Kumar and B. C. Saha, \textit{Phys. Rev. A} \textbf{59}, 1273 (1999). [Preview Abstract] 

K1.00047: PHOTON INTERACTIONS WITH ATOMS, IONS AND MOLECULES; STRONG FIELD LASER PROCESSES 

K1.00048: The ground state and doubly excited $^{1,3}$\textit{P}$^{o}$ states of the plasmaembedded Li$^{+}$ ion Sabyasachi Kar, Y.K. Ho With the recent advancement for laser plasmas in laser fusion laboratories [1] and with the recent experimental measurement on the doubly excited resonances in photoionization spectrum of Li$^{+}$ using the photonion mergedbeam at the Advanced Light Source [2], it is of interest to investigate the bound states and resonance states of Li$^{+}$ under the influence external environments produced by the chargeneutral background such as that of a plasma. The plasma effect is taken care of by using a screened Coulomb potential obtained from the Debye model. A correlated wave function has been used to represent the correlation effect between the charged particles. The ground state of Li$^{+}$ in plasmas for different screening parameters has been estimated in the framework of RayleighRitz variational principle. In addition, a total of 18 resonances (9 each for $^{1}P^{o}$ and $^{3}P^{o}$ states) below the $n=$2 Li$^{+}$ thresholds has been estimated by calculating the density of states using the stabilization method. The resonance energies and widths for various Debye parameters ranging from infinity to a small value for these $^{1,3}P^{o}$ resonance states are reported. [1] S . NaKai, K. Mima\textbf{,} \textit{Rep. Prog. Phys. }\textbf{67}, 321 (2004). [2] S. W. J. Scully \textit{et al},\textit{ J. Phys. B} \textbf{39}, 3957 (2006). [Preview Abstract] 

K1.00049: Photoelectron momentum spectra for multiphoton ionization of Hydrogen atoms by intense laser pulses Serge Ovchinnikov, Joseph Macek Full threedimensional electron momentum distribution for multiphoton ionization of Hydrogen atoms by intense laser pulses are calculated by solving the timedependent solutions of Schr\"{o}dinger equation on a threedimensional lattice in a scaled coordinate representation (CSLTDSE). This approach allows one to circumvent many difficulties related to the propagation of wave function to macroscopic distances. [Preview Abstract] 

K1.00050: Efficient Photoionization Loading of Ytterbium and Indium Ion Traps LiBang Wang, Tuan Nguyen, Martin Schauer, Justin Torgerson We aim to perform precision optical spectroscopy on narrow transitions of In$^{+}$ and Yb$^{2+}$ to search for possible time variation of finestructure constant $\alpha $. The high sensitivity of a transition frequency in Yb$^{2+}$ to $\dot {\alpha }$ and its insensitivity to external fields make it one of the best systems to test the time variation of finestructure constant. In this report, we present a simple and efficient method to load a Paul trap with In$^{+}$ and Yb$^{+}$ ions. Resonant lasers from blue laser diodes at 410 nm and 399 nm are used to excite 5$^{2}$P$_{1/2}$6$^{2}$S$_{1/2}$ transition of In and 6$^{1}$S$_{0}$6$^{1}$P$_{1}$ transition of Yb, respectively. A second photon from the same 410 nm laser drives the In atoms into the continuum, while the Yb atoms are excited to highlying Rydberg states by the same 399 nm laser and then subsequently ionized by the presence of a strong RF field. The progress of laser cooling of single trapped In$^{+ }$and Yb$^{+}$ ions, the proposed method of producing doublyionized Yb$^{2+}$ ions, and our approach using a frequencycomb laser for direct spectroscopy of clock transitions will be discussed. This work is supported by Los Alamos National Laboratory LDRD. [Preview Abstract] 

K1.00051: Multiphoton Ionization of Hydrogen Atoms in a Circularly Polarized Strong Radiation Field A.S. Titi, G.W.F. Drake The scattering matrix for the multiphoton ionization of a hydrogen atom in a circularly polarized strong radiation field, where the Coulomb potential is also included, is calculated. This leads to a divergent scattering matrix. By carrying out a unitary transformation to a frame in which the electron sees an oscillating nucleus, the singularity can be isolated and removed. The expression for the resulting nonsingular scattering matrix is written in terms of Bessel functions (representing direct single scattering) and Anger functions (representing rescattering). Both contributions interfere quantum mechanically. Intuitively, this provides a direct link to a path integral formulation of the problem. Finally, to compare our calculations with other calculations and to experimental results, the angular distribution of the ejected electrons is computed. [Preview Abstract] 

K1.00052: Anion and cation formation following Cl (1s) and S (1s) excitation in the SOCl$_2$ molecule L.C. Coutinho, G.G.B. de Souza, A.S. Schlachter, W.C. Stolte, Amphol Wongjamras The ionization of deep corelevel electrons is normally followed by a complicated array of processes involving cascading Auger mechanisms and giving rise to highly charged species. In contrast, the ionization of shallow corelevel electrons in molecules is usually followed by Auger processes involving the depletion of valenceshell electrons. We have recently shown that the Cl (1s) and S (1s) excitation of the chloroform (CHCl$_3$) and dimethylsulfoxide (CH$_3$SOCH$_3$) molecules leads to the formation of a rich array of positive and negative ions. Anion formation is particularly interesting due to the low probability of formation; they usually originate from decay pathways distinct from the pathways associated with cation formation. In the present work, cationic and anionic mass spectrometry results are presented for the SOCl$_2$ molecule, excited both in the Cl (1s) and in the S (1s) edges in experiments at the ALS beamline 9.3.1. [Preview Abstract] 

K1.00053: Repulsive Rydberg States and Dissociative Ionization Lutz Huwel, Hong Chen We have performed experimental studies of the competition between direct and dissociative ionization of Na$_{2}$ in single rovibrational levels of the 2$^{1}\Pi _{g}$ state. Excitation and ionization of the molecules is achieved in a molecular beam and with a twocolor, threephoton opticaloptical double resonance (OODR) technique. Total excitation energies range from about 700 to about 1400 cm1 above threshold for ground state dissociative ionization. Discrimination of fragment atomic Na$^{+}$ from molecular Na$_{2}^{+}$ ions is accomplished with a linear TimeofFlight spectrometer. We observe Na$^{+}$:Na$_{2}^{+}$ ion ratios ranging from about 0.05 to a about 0.15. We have developed a semiclassical model that accounts reasonably well for the observed behavior of the ratio. The model is based on the assumption that dissociative ionization occurs in competition between autoionization and dissociation along repulsive neutral Rydberg states converging to the Na$_{2}^{+}$ 1$^{2}\Sigma _{u}^{+}$ potential. Single adjustable model parameter is the autoionization lifetime. A chisquare procedure yields quite reasonable agreement with the experimental data suggesting autoionization lifetimes of the order of the corresponding Bohr orbit time. Details of the experiment and the model will be presented. [Preview Abstract] 

K1.00054: Electroncorrelation induced blueshift of oscillator strength in photoabsorption by clusters Himadri Chakraborty, Mohamed Madjet, Steve Manson We performed investigations on the role of electron correlations in the photoabsorption of several sodium metalclusters and fullerenes. We describe the electronic structure of the valence electron cloud by the Local Density Approximation (LDA) after representing the residual ions by a classical spherical jellium background. The response of the system to an external electromagnetic field is calculated by an independent particle (IP) LDA scheme that completely disregards electronelectron correlations. For all systems considered the IP result of photoabsorption cross section is characterized by predominant oscillator strength (OS) density below the first ionization threshold, the discrete part of the spectrum. We carried out separate calculations by appropriately including the electron correlation in a time dependent LDA frame. The resulting absorption cross sections generically indicate the transfer of OS density above the first ionization threshold as a direct consequence of the correlation. The blueshifted OS density forms the plasmon resonances, the character of which, however, depends on the specifics of geometry and size of the system. [Preview Abstract] 

K1.00055: Emission of a Correlated Photo Electron Pair from Molecular Hydrogen: A T. Young Double Slit Experiment Thorsten Weber et al. We have studied experimentally the influence of the molecular alignment and spacing on the electron emission from a two body Coulomb potential induced by single photon absorption with 130, 160, 200 and 240 eV circular polarized light at the Advanced Light Source. Applying successfully the technique of COLTRIMS, it was possible to measure fully differential cross sections (FDCS) for the photo double photo ionization of hydrogen for fixed in space molecular orientations by detecting three particles in coincidence. The measurements covered 4$\pi $ solid angle. We present angular distributions of the electrons studying the influence of diffraction, symmetry effects, selection rules and molecular orientations in body fixed frames. Thus for the first time a T. Young double slit experiment of a correlated electron pair inside a hydrogen molecule can be presented. We can illustrate the evolution from knockoff to shakeoff processes and the interference of single particles as well as correlated pairs, while changing the deposed photon energy as well as the energy sharing of the two electrons. In addition the angular distributions show a distinct dependency on the Kinetic Energy Release (KER) of the recoiling ions, e.g. the size of the molecular double slit. The experimental results are also compared with quantum mechanical calculations. [Preview Abstract] 

K1.00056: Double Photoionization of Adamantane Ralf Wehlitz, Max Young, Pavle Juranic We have measured doubletosingle ionization crosssection ratios of adamantane (C$_{10}$H$_{16}$) in gas phase using photons of the Synchrotron Radiation Center (SRC). Adamantane, which is the first in the family of diamandoids, has a unique cage structure  the same structure that is found in the diamond crystal lattice. Thus, adamantane can be viewed as the smallest piece of diamond. Its cage structure prompted us to measure the first doubletosingle photionization ratios over a large photon energy range because previously we have found a surprising relation between modulations in that ratio and geometrical dimensions of a C$_{60}$ cluster\footnote{P.\ N.\ Jurani\'c, D.\ Luki\'c, K. Barger, R.\ Wehlitz Phys.\ Rev.\ Lett. {\bf 96}, 023001 (2006).}. However, in contrast to C$_{60}$, adamantane does not have a ``regular'' structure and has additional hydrogen atoms attached to its cage. We will present our new data for adamantane and compare them to C$_{60}$. [Preview Abstract] 

K1.00057: Modulations in the DoubletoSingle Photoionization Cross Section Ratio of Benzene Pavle Jurani\'c, Ralf Wehlitz, Max Young In our previous experiments, we have observed the existence of modulations in the relative doubletosinglephotoionization cross section ratio of C$_{60}$. The de Broglie wavelengths of the excess(above double ionization threshold) energies of these modulations closely matched interatomic distances within the C$_{60}$ molecule \footnote{P. N. Jurani\'c, D. Luki\'c, K. Barger, and R. Wehlitz, Phys. Rev. Lett. {\bf 96}, 023001 (2006)}. We have conducted further experiments with benzene, which has a much simpler structure than C$_{60}$, to find out whether these modulations exist and can be similarly linked to interatomic distances in other molecules. The results of the experiment indicate that there seems to be such modulations in benzene. [Preview Abstract] 

K1.00058: Extension of High Harmonic Generation Cutoff via Coherent Control of Intense FewCycle Chirped Laser Pulses Juan J. Carrera, ShihI. Chu We present an \textit{ab initio} quantum investigation of the highorder harmonic generation (HHG) cutoff extension using intense fewcycle chirped laser pulses. For fewcycle chirped driving laser pulse, it is shown that significant cutoff extension can be achieved through the optimization of the chirping rate parameters. The HHG power spectrum is calculated by solving accurately and efficiently the timedependent Schr\"{o}dinger equation by means of the timedependent generalized pseudospectral method. The timefrequency characteristics of the HHG power spectrum are analyzed in details by means of the wavelet transform of the timedependent induced dipole acceleration. In addition, we perform classical trajectory simulation of the strongfield electron dynamics and electron return map. It is found that the quantum and classical results provide complementary and consistent information regarding the underlying mechanisms responsible for the substantial extension of the cutoff region. [Preview Abstract] 

K1.00059: Selfinteractionfree TDDFT for nonperturbative treatment of multiphoton processes of heteronuclear diatomic molecular systems in intense laser fields John Heslar, ShihI. Chu We present a \textit{selfinteractionfree }timedependent densityfunctional theory (TDDFT) with proper asymptotic \textit{longrange} potential for nonperturbative treatment of multiphoton processes of manyelectron heteronuclear molecular systems in intense laser fields. A \textit{timedependent} \textit{generalized pseudospectral} method is developed with the use of a new massweighted prolate spheroidal coordinate system for accurate solution of the electronic structure and TDDFT equations for twocenter heteronuclear diatomic systems. The procedure allows \textit{nonuniform} and optimal spatial grid discretization of the Hamiltonian in the adapted prolate spheroidal coordinates and a split operator scheme in \textit{energy} representation is used for the time propagation of individual molecular spin orbital's in space and time. The theory is applied to a detailed \textit{allelectron} study of highorder harmonic generation (HHG) and multiphoton ionization processes of CO in intense laser fields. Both even and oddorder harmonics are predicted for the CO molecule. [Preview Abstract] 

K1.00060: Relativistic Dynamics of highly charged hydrogenlike systems exposed to intense highfrequency electromagnetic fields Eva Lindroth, S{\O}lve Selst{\O}, Jakob Bengtsson We solve the time dependent Dirac equation in a basis consisting of the eigenstates of the field free Hamiltonian $H_0=c \mbox{\boldmath $\alpha$} \cdot {\bf p} + V(r)+ m c^2 \beta$. The dynamics induced by the time dependent perturbation, $H'_v=c \mbox{\boldmath $\alpha$} \cdot {\bf A}({\bf r},t)$ in the velocity gauge, or equivalently $H'_l={\bf r} \cdot {\bf E}({\bf r},t) (1\mbox{\boldmath $\alpha$} \cdot \hat{\bf k})$ in the length gauge, is resolved by solving the first order differential equation arising from the expansion. The number of continuum states needed in order to get converged results is reduced by complex scaling of the coordinates, $r \rightarrow r e^{i \theta}$. We investigate the importance of relativistic effects for various field strengths, $E_0$, and nuclear charges by comparing the solutions of the Dirac equation with those of the Schr{\"o}dinger equation. The dynamics is described both within and beyond the dipole approximation (${\bf A}({\bf r},t) \approx {\bf A}(t)$). For high $E_0$ and high photon energy, $\hbar \omega$, it is clear that this approximation breaks down. However, for increasing $Z$, the electron is increasingly tightly bound, which to some extent reduces the importance of nondipole effects. [Preview Abstract] 

K1.00061: Highharmonic generation with relativistic laser intensities Carl Schroeder, Eric Esarey, Wim Leemans A method for producing hard xrays via highharmonic generation using ultraintense lasers is proposed. The method relies on cavitation and ion channel formation by the ponderomotive force of a short, ultraintense laser pulse or the space charge force of a dense, energetic electron beam. A second laser produces high harmonics in the electronfree cavity. A counterpropagating laser is used to eliminate the longitudinal motion owing to the magnetic component of the Lorentz force in the relativistic regime. A counterpropagating laser pulse train is proposed for quasiphase matching. This method enables the reach of highharmonic generation to be extended to the sub\AA\ regime. [Preview Abstract] 

K1.00062: Manymode Floquet theoretical approach for probing high harmonic generation in intense frequencycomb laser fields SangKil Son, ShihI Chu We extend the manymode Floquet theorem (MMFT) [Chu and Telnov, Phys.\ Rep.\ \textbf{390}, 1 (2004)] for the investigation of high harmonic generation of a twolevel system driven by intense frequencycomb laser fields. The frequency comb structure generated by a train of short laser pulses can be represented by a combination of the main frequency and the repetition frequency. The MMFT allows nonperturbative and accurate treatment of the interaction of a quantum system with the frequency comb laser fields. We observe that harmonic generation of the twolevel system is dramatically enhanced by controlling the repetition frequency and the phase difference between pulses, due to simultaneous resonances. [Preview Abstract] 

K1.00063: The Effect Of Focal Geometry On Radiation From Atomic Ionization In An Ultrastrong/Ultrafast Laser Field Isaac Ghebregziabher, B.C. Walker We use a tunnelingMonteCarlo model to calculate the dynamics and emitted Larmor radiation from electrons ionized in an ultrashort/ultraintense pulsed laser focus over the intensity range from 10$^{17}$ to 10$^{20}$ W/cm$^{2}$. We find the spatial variation of a laser field can no longer be neglected at laser intensities leading to relativistic effects. Adopting a onedimensional or plane wave approximation overestimates the total radiated energy by a factor as high as two orders of magnitude. Despite this, the spectral amplitude of the radiated highenergy photons from ionization in a laser focus is as high as that in the plane wave case since the laser focus imparts an extra boost of speed for electrons exiting the focus. Moreover, ionization in a laser focus limits the effective radiation volume to a few fraction of $\mu $m$^{3}$ leading to more coherent radiation. For the ionization of Na$^{10+}$ in a laser focus of intensity 1.22 10$^{20}$ W/cm$^{2}$, we find the peak radiation yield extending to photon energies of 580eV. In the plane wave case, we find radiation extending to photon energies of 560eV. [Preview Abstract] 

K1.00064: Semiclassical theory of diffraction imaging in strong laser fields Ryan Murray, Misha Ivanov We present an analysis of how intense, fewcycle infrared laser pulses can be used to image the structure of small molecules with nearly 1 fs temporal and sub{\AA} spatial resolution. We perform numerical calculations using semiclassical techniques to obtain diffraction images of monatomic and diatomic nuclei. We then compare this to fully quantum calculations. We also discuss the strengths and weaknesses of our method, and why the semiclassical approach is more tractable than typical quantum calculations. [Preview Abstract] 

K1.00065: EIT AND QUANTUM MEMORY / COHERENT CONTROL 

K1.00066: Characterization of decoherence in electromagnetically induced transparency for applications in storage of light Eden Figueroa, Juergen Appel, Frank Vewinger, Alexander Lvovsky Electromagneticallyinduced transparency (EIT) has many applications in quantum information, particularly in quantum memory for light [1]. These applications require understanding of the phenomena responsible for decoherence in such processes. Insight into this question can be gained by measuring the width of the EIT resonance as a function of the pump field intensity. We report characterization of EIT resonances in the D1 line of Rb 87 under various experimental conditions. The dependence of the EIT linewidth on the power of the control field was investigated, at various temperatures, for lambda level configurations associated with different hyperfine levels of the atomic ground state as well as magnetic sublevels of the same hyperfine level. Strictly linear behavior was observed in all cases. Our results were inconsistent with a widely accepted theory where population exchange between the ground levels is assumed to be the main decoherence mechanism [2]. We therefore formulated a new theory assuming pure dephasing (decay of offdiagonal matrix elements) as the new mechanism. Our data shows this theory to be in good agreement with our experiments. 1. D. F. Phillips, A. Fleischhauer, A. Mair, R. L. Walsworth, and M. D. Lukin, Phys. Rev. Lett. \textbf{86}, 783 (2001). 2. H. Lee, Y. Rostovtsev, C. J. Bednar, and A. Javan, Appl. Phys. B \textbf{76}, 33 (2003). [Preview Abstract] 

K1.00067: Progress Towards High Efficiency AtomPhoton Interface with Atomic Ensembles Alex Nemiroski, Philip Walther, Alexey Gorshkov, Alexander Zibrov, Mikhail Lukin We describe our progress towards the generation and manipulation of narrowbandwidth single photons and entangled photon pairs using a roomtemperature ensemble of 87Rb atoms. Our method involves the creation of a collective atomic coherence via Raman scattering and projective measurement, followed by the coherent transfer of this atomic coherence to photons using electromagnetically induced transparency (EIT). We describe our current efforts towards developing a high performance system. These include optimization of the atomic level scheme, timing and preparation sequence, and buffer gas pressures. [Preview Abstract] 

K1.00068: Manyparticle effects in the propagation of slow light through atomic gases Iyad Mahmoud, KarlPeter Marzlin, Barry Sanders The optical properties of an atomic gas, including the dramatic reduction of the group velocity of light in electromagnetically induced transparency, usually grow with the density of atoms in the medium. However, in atomic gases of high density the resonant dipoledipole interaction (DDI) will generate atomatom correlations that can significantly alter the optical response of the medium. We present a theoretical analysis of the influence of DDI on the optical properties of a gas of threelevel atoms in $\Lambda$ configuration in which electromagnetically induced transparency is possible. Our novel method combines dressed states of quantum optics with the Keldysh diagram technique of nonequilibrium manybody theory and is particularly suited to describe atomatom correlations in systems exhibiting coherent population trapping. We derive the susceptibility of the atomic gas from the properties of the manybody Green's function and analyze its dependence on the temperature and density of the gas. The diagram technique also allows us to develop an intuitive picture of the physics of the propagation of light through a dense gas. [Preview Abstract] 

K1.00069: Modeling Lossless Negative Refraction Timothy Bragdon, Susanne Yelin We use a model of twolevel systems to simulate negative refractive index without absorptive losses due to gain enhancement. We compare this with our earlier ideas on negative refraction based on electromagnetically induced transparency (EIT). Then, we report the effects of phase noise on the resultant signal for import in signal fidelity issues. [Preview Abstract] 

K1.00070: Negative refraction without absorption: coherence effects, gain and local field corrections J\"urgen K\"astel, Michael Fleischhauer, Gediminas Juzeliunas, Susanne F. Yelin, Ronald L. Walsworth Negative refraction of electromagnetic radiation is currently one of the most active areas of photonics research. Despite remarkable recent progress, a key challenge remains the realization of negative refraction \textit{without absorption}. We discuss different ways to alleviate this problem: the coupling of an electric and a magnetic resonance together with quantum interference effects similar to EIT; compensation of absorption by introducing gain media. Futhermore surprisingly ClausiusMossotti local field corrections for magnetodielectric media in the high density limit result always in negative refraction with vanishing absorption. [Preview Abstract] 

K1.00071: Large fractional delay for slow and stored light in atomic vapor Irina Novikova, David Phillips, Ronald Walsworth Large fractional delay is important in slow and stored light for many potential applications, from quantum communication to photonics. We have achieved large fractional delay for slow and stored light in Rb vapor using temporallyshaped control fields. Combined with amplification provided by selfrotation, we can produce slow and stored light pulses with large fractional delay and minimal distortion or attenuation. [Preview Abstract] 

K1.00072: Coherent quantum optical control with subwavelength resolution Alexey Gorshkov, Mikhail Lukin We propose a new method for coherent optical farfield manipulation of quantum systems with resolution that is not limited by the wavelength of radiation. Our method makes use of the manipulation of atomic response with a control beam under the conditions of Electromagnetically Induced Transparency. The idea is that within a small distance $\Delta x$ around a zero of a strong control field (e.g. a standing wave or a beam with a doughnutlike cross section) an atom will not be saturated, but it will be saturated outside of $\Delta x$, where $\Delta x$ can be made arbitrarily small by increasing the power of the control field. As a result, two atoms can respond very differently to the control field or other simultaneously applied fields despite being separated by much less than a wavelength. This approach can be used for selective coherent manipulation of proximally spaced ions, atoms, or solidstate defects. Practical performance of this technique and its potential applications to quantum information processing are discussed. [Preview Abstract] 

K1.00073: Cold Atoms inside a HollowCore PhotonicCrystal Fiber Vlatko Balic, Michal Bajcsy, Alexander Zibrov, Vladan Vuletic, Mikhail Lukin Cold atoms confined inside a hollowcore photoniccrystal fiber with core diameters of a few photon wavelengths are a promising medium for studying nonlinear optical interactions at extremely low light levels. The high electric field intensity per photon, large optical depths, and interaction lengths not limited by diffraction are some of the unique features of this system. We describe recent progress in our experiment that uses a combination of magnetic trapping and a reddetuned optical dipole trap to transfer cold Rb87 atoms into the hollowcore fiber. We present data on transfer efficiencies as well as preliminary experiments towards nonlinear optics with fewphoton pulses. [Preview Abstract] 

K1.00074: ATOMIC & MOLECULAR SPECTROSCOPY 

K1.00075: Atomic transitions among the levels of $3d^6$, $3d^54s$, $3d^54p$ configurations in Fe III Narayan C. Deb, Alan Hibbert We present a configuration interaction (CI) calculation for the finestructure levels of Fe III belonging to $3d^6$, $3d^54s$ and $3d^54p$ configurations. All 136 LS states of these three configurations are considered. Using HartreeFock functions for 1s, 2s, 2p, 3s, 3p and 3d we have generated furthers radial functions for 4s, 4p, 4d, 4f, 5s, 5p, 5d, 5f and 6p orbitals. 4s and 4p orbitals are taken as spectroscopic and remaining orbitals taken as either correction or correlation orbitals. Relativistic effects are accounted for through Mass correction and Darwin terms in addition to an approximate form of the twobody spinorbit interaction term. Ab initio finestructure levels are then finetuned to bring them in line with the available NIST values. We then calculate the oscillator strengths and transition probabilities for all possible E1 transitions. CIV3 program of Hibbert [{\it{Comp. Phys. Commn.}} {\bf{9}} 141 (1975)] has been used for the present calculation. The results will be presented at the conference. [Preview Abstract] 

K1.00076: Energy Levels and Radiative Rates in AlLike Copper G.P. Gupta, A.Z. Msezane Excitation energies from ground state for 98 finestructure levels and oscillator strengths and radiative decay rates for all electricdipoleallowed and intercombination transitions among the finestructure levels of the terms belonging to the (1s$^{2}$2s$^{2}$2p$^{6})$3s$^{2}$3p, 3s3p$^{2}$, 3s$^{2}$3d, 3p$^{3}$, 3s3p3d, 3p$^{2}$3d, 3s3d$^{2}$, 3s$^{2}$4s, 3s$^{2}$4p, 3s$^{2}$4d, 3s$^{2}$4f, and 3s3p4s configurations of Cu XVII, are calculated using extensive CI wave functions [1]. The important relativistic effects in intermediate coupling are incorporated through the BreitPauli Hamiltonian. We have also investigated the effects of electron correlations on our calculated data, particularly on the intercombination transitions, by including orbitals with up to n=5, considering up to three electron excitations from the valence electrons of the basic configurations and including a large number of configurations. Our adjusted excitation energies are in excellent agreement with experimental results [2]. We find enormous mixing among several finestructure levels, making it very difficult to identify them correctly. Our radiative lifetimes of the finestructure levels agree excellently with those of Ref. [3]. 1. A. Hibbert, Comput. Phys. Commun. \textbf{9}, 141 (1975). 2. T. Shirai \textit{et al}., J. Phys. Chem. Ref. Data \textbf{20}, 12 (1991). 3. E. Trabert \textit{et al}., J. Opt. Soc. Am. B \textbf{5}, 2173 (1988) [Preview Abstract] 

K1.00077: Hyperfineinduced \boldmath{$2s2p\,^3P_0  2s^2\,^1S_0$} transition in Belike ions K.T. Cheng, M.H. Chen The hyperfineinduced $2s2p\,^3P_0  2s^2\,^1S_0$ transition rate for Belike $^{47}$Ti$^{18+}$ is recently measured in a storagering experiment by Schippers {\it et al.}\ [Phys.Rev.Lett.\ {\bf 98}, 033001 (2007)]. The measured value of 0.56(3) s$^{1}$ is almost 60\% larger than the multiconfiguration DiracFock value of 0.356 s$^{1}$ by Marques {\it et al.}[Phys. Rev. A {\bf 47}, 929 (1993)]. In this work, we use a largescale relativistic configurationinteraction method to calculate this hyperfineinduced rate. Coherent hyperfinequenching effects between the $2s2p\,^3P_1$ and $^1P_1$ states are included in a radiation damping formalism. Contrary to the findings of Marques {\it et al.}, contributions from the $^1P_1$ state are substantial and lead to much better agreement with experiment. [Preview Abstract] 

K1.00078: Dependence of Ramsey fringe width on parameters James Supplee, PaulMichael Huseman A Ramsey pulse pair (two coherent pulses separated in time) clearly has much longer duration than either pulse would have by itself. This gives the Ramsey pair a narrower energy spectrum than the single pulse and therefore a fundamental spectroscopic advantage in resolution. Even if one uses a single ``longtype'' pulse (duration equal to that of the entire Ramsey pair including dark time) instead, the Ramsey pair spectrum can still be narrower. Under a broad range of circumstances, the central peak of the Ramsey pair's spectrum is only about 0.6 times as broad as that of a single longtype pulse. This ``narrowing factor'' of 0.6 does not always carry over directly to a comparison of peak widths as measured by population inversion. We will present results of calculations that explore how this narrowing factor (Ramsey versus single longtype pulse) depends on parameters such as pulse duration, dark time, and atomic inversion. [Preview Abstract] 

K1.00079: Branching Ratios for Hydrogenic Zeeman States from Classical Mechanics Michael W. Horbatsch, Eric A. Hessels, Marko Horbatsch In previous work we applied the classical Larmor radiation formula to calculate the lifetimes of hydrogenic Zeeman levels on the basis of classical mechanics and semiclassical quantization [1]. For the fieldfree case excellent agreement with quantum mechanics was obtained for total lifetimes, and good agreement for branching ratios [2]. In this work we report on (semi)classical results for the branching ratios of Zeeman levels based on HamiltonJacobi perturbation theory. The branching ratios are calculated using numerical solutions of the trajectories and their Fourier analysis. While the agreement is good for partially summed branching ratios, some discrepancies with quantum results are found at the level of the full branching ratios. \newline [1] Phys. Rev. A 72, 033405 (2005) \newline [2] Phys. Rev. A 71, 020501(R) (2005). [Preview Abstract] 

K1.00080: Core excitation effects on oscillator strengths for transitions in four electron atomic systems T. N. Chang, Yuxiang Luo By including explicitly the electronic configurations with two and three simultaneously excited electronic orbital, we have extended the BSCI (Bspline based configuration interaction) method [1] to estimate directly the effect of inner shell core excitation to oscillator strengths for transitions in fourelectron atomic systems. We will present explicitly the change in oscillator strengths due to core excitations, especially for transitions involving doubly excited states and those with very small oscillator strengths. The length and velocity results are typically in agreement better than 1{\%} or less. [1] Tunan Chang, in \textit{Manybody Theory of Atomic Structure and Photoionization, }edited by T. N. Chang (World Scientific, Singapore, 1993), p. 21347; and T. N. Chang and T. K. Fang, Elsevier Radiation Physics and Chemistry \textbf{70}, 173190 (2004). [Preview Abstract] 

K1.00081: Relativistic manybody calculations of lifetimes, rates, and line strengths of multipole transitions between $3l^{1}4l'$ states in Nilike ions U.I. Safronova, A.S. Safronova, P. Beiersdorfer Transition rates and line strengths are calculated for electricmultipole (E1, E2, and E3) and magneticmultipole (M1, M2, and M3) transitions between $3s^23p^63d^94l$, $3s^23p^53d^{10}4l$, and $3s3p^63d^{10}4l$ states (with $4l$ = $4s$, $4p$, $4d$, and $4f$) in Nilike ions with the nuclear charges ranging from $Z$ = 34 to 100. Relativistic manybody perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded multipole matrix elements. Transition energies used in the calculation of line strengths and transition rates are from secondorder RMBPT. Lifetimes of the $3s^23p^63d^94s$ and $3s^23p^63d^94d$ levels are given for $Z$ = 34100. Taking into account that calculations were performed in a very broad range of $Z$, the most of the data are presented in graphs as $Z$ dependences. The full set of data is given only for Nilike Mo and W ions. These atomic data are important in modeling of Mshell radiation spectra of heavy ions generated in electron beam ion trap experiments and for fusion research. [Preview Abstract] 

K1.00082: Correlation and relativistic effects for the $4d  nl$ multipole transitions in Pdlike ions R. Bista, R. Bruch, U.I. Safronova, H. Merabet Wavelengths, transition rates, and line strengths are calculated for the 85 possible multipole (E1, M1, E2, M2, E3, M3) transitions between the excited $4p^64d^{9}4f$, $4p^64d^{9}5l$, $4p^54d^{10}4f$, and $4p^53d^{10}5l$ states and the ground $4p^64d^{10}$ state in Pdlike ions with the nuclear charges ranging from $Z$ = 47 to 100. Relativistic manybody perturbation theory (RMBPT), including the Breit interaction, is used to evaluate energies and transition rates for multipole transitions in holeparticle systems. This method is based on the relativistic manybody perturbation theory, agrees with MCDF calculations in lowestorder, includes all secondorder correlation corrections, and includes corrections from negative energy states. The calculations start from a [Zn]$4p^64d^{10}$ DiracFock potential. Firstorder perturbation theory is used to obtain intermediatecoupling coefficients, and secondorder RMBPT is used to determine the matrix elements. The contributions from negativeenergy states are included into the secondorder E1, M1, E2, M2, E3, and M3 matrix elements. The resulting transition energies and transition rates are compared with experimental values and with results from other recent calculations. The $Z$ dependence of the energy splitting for all triplet terms of the $4p^64d^{9}4f$ and $4p^64d^{9}5l$ configurations are shown for $Z$ = 47100. [Preview Abstract] 

K1.00083: Spectral Analysis of Hydrogenic Ions Embedded in Strongly Coupled Plasmas Yew Kam Ho, H.F. Lai, Y.C. Lin In the present work, we report theoretical calculations for spectral properties of hydrogenic ions He$^{+}$, Li$^{2+}$, Be$^{3+}$, B$^{4+}$, and C$^{5+}$ embedded in strongly coupled plasmas. The hydrogenic $1s, 2p$, and $3p $states have been investigated using the ionsphere (IS) model [1]. The spectral properties including the ground state energy, the excitation energy, and the oscillator strength for the $1s2p$ and $1s3p$ transitions are calculated using Bspline basis. Results have been obtained as functions of the ionsphere radius R in the IS model. Our calculated values can be used to deduce the temperature and the electronic charge density for strongly coupled plasmas. A comparison with an earlier calculation [2] will be presented at the meeting. \newline [1] S. Ichimaru, \textit{Rev. Mod. Phys}. \textbf{54}, 1017 (1982). \newline [2] A. N. Sil, B. Saha, and P. K. Mukherjee,\textit{ Inter. J. of Quantum Chem. }\textbf{104}, 903 (2005) [Preview Abstract] 

K1.00084: The Seventh and Eighth Spectra of Cerium (Ce VII and Ce VIII) Tauheed Ahmad, Yogi Joshi The spectrum of cerium was recorded in the 2000 {\AA}  350 {\AA} wavelength region on a 3m normal incidence spectrograph using triggered spark and sliding spark sources. The seventh and eight spectra of cerium have never been reported. Resonance lines in both spectra have been positively identified and the ground states for both spectra have also been established. Below 500 {\AA} there is an overlap of many spectra of different ions arising out of inner shell felectron excitations and which has complicated the analyses. The latest stage of the analyses will be presented. [Preview Abstract] 

K1.00085: Absolute Wavelength Measurements of Transitions in H and Helike Argon and Sulfur Ions with a Novel Crystal Spectrometer Hjalmar Bruhns, Johannes Braun, Katharina Kubi\v cek, Jos\'e R. Crespo L\'opezUrrutia, Joachim Ullrich Highprecision absolute and relative wavelength measurements of highly charged Hlike and Helike ions have been carried out at the Heidelberg Electron Beam Ion Trap (EBIT) with a novel crystal spectrometer applying the Bond method. The Ar$^{16+}$ results, with error bars of $\delta\lambda / \lambda < 5 \cdot 10^{6}$, are the most precise absolute wavelength measurements in highly charged ions up to now and confirm recent relativistic and QED calculations for this range of $Z$. This level of accuracy was reached by introducing a new method for the determination of the Bragg angle using two laser beams as fiducials. These make the commonlyused entrance slits unnecessary, thus reducing the time necessary for reaching high statistical significance, and also eliminating various systematic geometric error sources. A comparison to theory and other experimental results will be presented. [Preview Abstract] 

K1.00086: Comparison of the Dependence of Saturated Absorption Spectra of 87Rb D2 line on the Beam Size and the Intensity HeungRyoul Noh, Geol Moon, Huy Diep Do We measure the saturated absorption spectra of the $^{87}$Rb D$_2$ line by varying the size and the intensity of the pump beam. We found that the increase of the beam size is almost equivalent to the increase of the pump beam intensity. This is because both the beam size and intensity influence the interaction of atoms with the pump laser beam, and especially the variation of the beam size means the variation of the transit time of atoms crossing the beam crosssection. However, we found that there exits difference for the signal of $F_{g}=2 \rightarrow F_{e}=3$ closed transition line. This can be explained by the saturation effect. We compared the experimental results with the theoretical calculations based on the rate equation model, and found good agreement between them. [Preview Abstract] 

K1.00087: Revised Analysis and Configuration Interaction in Mo~{\sc VI} Joseph Reader Mo {\sc vi}, with ground term 4p$^{6}$4d $^{2}$D, has a simple oneelectron spectrum 4p$^{6}$\textit{nl}4p$^{6}n^{\prime}l^{\prime}$ as well as a more complex spectrum arising from innershell excitations 4p$^{5}$4d$^{2 }$and$^{ }$4p$^{5}$4d5s. A few years ago we observed the spectrum of Mo~{\sc vi} from 200 to 5300 {\AA} with a slidingspark and the 10.7m normal and grazingincidence spectrographs at NIST. We revised a number of the known even levels of the oneelectron spectrum [1] and confirmed the ionization limit [1],$^{ }$which was based largely on the Penning discharge observations of Romanov and Striganov [2]. A number of Romanov and Striganov's line identifications were also revised. Our results have not yet been published. More recently, we revisited the 4p$^{6}$(4d+5s)4p$^{5}$(4d$^{2}$+4d5s) transitions and revised several of the coreexcited levels [3]. Some levels of 4p$^{5}$4d$^{2}$ are highly mixed with oneelectron levels, resulting in transitions at longer wavelengths between 4p$^{5}$4d$^{2}$ and oneelectron levels. This provides accurate connections between the ground term and some highlyexcited levels and thus highly accurate Ritztype wavelength predictions for resonance transitions. Improved values have been obtained for all of the energy levels and a new leastsquares fit for the odd configurations carried out. [1] B. Edl\'{e}n, et al., Phys. Scr. \textbf{32}, 215 (1985). [2] N. P. Romanov and A. R. Striganov, Opt. Spectrosc. (USSR) \textbf{27}, 8 (1969). [3] A. Kancerevicius et al., Lith. Phys. J. \textbf{31},143 (1991). Supported by Office of Fusion Energy Sciences of D.O.E. [Preview Abstract] 

K1.00088: Optical transitions among Rydberg statesan ideal avenue for measuring both the fine structure and Rydberg constants accurately Joseph Tan, Peter Mohr The fine structure and Rydberg constants play crucial roles in tests of QED and the Standard Model, in the International System of units (SI), and in the CODATA evaluation of fundamental constants. The extraordinary precision of femtosecondlaser frequency combs opens the possibility of directly measuring both the fine structure and Rydberg constants in an atomic system with high accuracy provided that the atomic system is engineered to be essentially free from poorlyunderstood complexities (such as nuclear structure). This new approach is attractive because optical frequency metrology has attained such high precision as to outpace the most detailed theory for even the simplest atom in nature, hydrogen. One avenue to explore involves the synthesis of hydrogenlike ions in special highorbital states engineered to make them better suited for measuring these two constants. In particular, the fine structure splitting would be magnified by a large nuclear charge $Z$, which is selected so that the measurementstransitions among these high orbital statesare in the domain of optical frequency combs. Progress in assessing the QED corrections to the Dirac theory for $^{20}$Ne$^{9+}$ as a test case is discussed. The advantages and challenges in realizing this new approach for accurately measuring both the fine structure and Rydberg constants are presented. [Preview Abstract] 

K1.00089: Determining the cesium $7d \, ^2 \! D_j$ hyperfine structure using twophoton resonant spectroscopy of a thermal beam Andrew Kortyna, Victor Fiore The hyperfine structures of the $7d \, ^2 \! D_{3/2}$ and $7d \, ^2 \! D_{5/2}$ states of $^{133}$Cs are determined through twophoton, laserinducedfluorescence spectroscopy of a thermal beam. Two singlemode externalcavity diode lasers provide narrow band radiation for resonant twostep excitation of the $7d \, ^2 \! D_j$ states. A servofeedback circuit locks one laser to the $6s \, ^2 \! S_{1/2} (F) \rightarrow 6p \, ^2 \! P_{3/2} (F')$ hyperfine transitions. Optical pumping of the ground hyperfine manifold is minimized by phase modulating this laser at 9.193 GHz. The second laser is scanned over the $6p \, ^2 \! P_{3/2} (F') \rightarrow 7d \, ^2 \! D_j (F'')$ transitions. Using various combinations of the ground and intermediate hyperfine levels (i.e., $F$ and $F'$), all hyperfine intervals of the $7d \, ^2 \! D_j$ states are observed. The scanned laser's relative frequency is calibrated through phase modulation; the resulting sidebands cause atomic features to be repeated at precise intervals. High accuracy is achieved by directly referencing the modulation frequency to the $^{87}$Rb $5s \, ^2 \! S_{1/2} (F=1) \leftrightarrow 5s \, ^2 \! S_{1/2} (F=2)$ ground state hyperfine transition using an atomic frequency standard. [Preview Abstract] 

K1.00090: Autoionizing Rydberg series in argon R.L. Brooks, B.M. van der Ende, C. Winslade, R.H. deLaat, N.P.C. Westwood Optical transitions from two microwave discharge excited states of argon have been observed using cavity ringdown spectroscopy. The two originate on the high lying levels, $3d[3/2]_2^\circ $and $3d[1/2]_1^\circ $ and terminate on the $nf'[5/2]_2 $ Rydberg (n=8 to 22) levels which, except for n=8, lie between the $^{2}$P$_{3/2}$ and $^{2}$P$_{1/2}$ ionization thresholds. In total 24 spectral lines have been observed. The quantum defect has been measured to significantly higher precision than previously and agrees with previous values. Our determination of the $^{2}$P$_{1/2}$ series limit also agrees with previous measurements signifying that Stark shifts (and presumably Stark broadening) are not expected to be significant. The line widths, however, are broad and increase monotonically with n (above 9) for reasons that are not entirely clear. We observe a nearly threefold jump in linewidth in going from n=8 to n=9, below and above the $^{2}$P$_{3/2}$ threshold, respectively. We propose that collisional broadening is the dominant mechanism but that electric field enhanced autoionization may also play a role. [Preview Abstract] 

K1.00091: Magnetic Resonance Reversals in Optically Pumped AlkaliMetal Vapor Fei Gong, YuanYu Jau, William Happer We report an unusual new phenomenon, peculiar sign reversals of the groundstate magnetic resonances and of the ``zerodip" resonance (Zeeman resonance at zero field) of opticallypumped, alkalimetal vapors. These anomalies occur when a ``weak" circular polarized $D$1 laser light is tuned to pump atoms predominantly from the lower groundstate hyperfine multiplet. One can understand the signal reversals in simple, semiquantitative way with reference to this distribution. uantitative computer simulations are in excellent greement with observations. [Preview Abstract] 

K1.00092: Two Photon Spectroscopy of Rubidium Using a GratingFeedback Diode Laser Shannon Mayer, Abraham Olson, Evan Carlson We describe an experiment for investigating the 5S 1/2 to 5D 5/2 twophoton transition in rubidium using a gratingfeedback diode laser operating at 778.1 nm. Tuning of the laser frequency over 4 GHz allows for the clear resolution of the Dopplerfree spectral features and accurate measurement of the hyperfine groundstate splitting. A direct comparison between Dopplerbroadened and Dopplerfree spectral features is possible because both are distinctly evident in the spectra. By modifying the polarization state of the two laser fields, the impact of electric dipole selection rules on the spectra is investigated. This experiment is a valuable addition to the advanced laboratory; it uses much of the same equipment as the singlephoton saturated absorption spectroscopy experiment performed on the 5S 1/2 to 5P 3/2 transition in rubidium at 780.24 nm and provides students with an opportunity to investigate characteristics of atomic spectra not evident in the singlephoton experiment. Moreover, rubidium twophoton transitions are of interest as new optical frequency standards due to their transition wavelength and narrow linewidth. [Preview Abstract] 

K1.00093: Temporal Photon Correlations and TwoPhoton Absorption in Alkali Metals Daniel Bennett, Brian Spector, Kyle Foster, John Caraher Virtualstate spectroscopy[1] (VSS) is a proposal to use temporal correlations between photons as a probe of the eigenstate composition of the virtual state involved in a twophoton absorption process. The technique relies upon measuring modulations in the twophoton absorption cross section as ``entanglement time'' and imposed delays vary on a femtosecond scale. Photon pairs produced via parametric downconversion are the basis for these experiments. We report studies of the constraints on observing these effects in Na and Rb. This work involves computer simulations of VSS for the $3s4s$ transition in Na and the $5s5d$ transition in Rb with the goal of establishing the parameters required for a successful experimental test. We also report on parallel laboratory investigations in support of this goal. [1] B.E.A. Saleh, B.M. Jost, H. B. Fei, M.C. Teich, Phys. Rev. Lett., \textbf{80} 3483 (1998) [Preview Abstract] 

K1.00094: Precision Lifetime Measurement of the Cesium 6$P_{3/2}$ State B.M. Patterson, T. Ehrenreich, R.J. Knize We have refined our atomic lifetime measurement technique\footnote{B.M. Patterson, C.D. Lindstrom, T. Takekoshi, J.R. Lowell, C. Villarreal, and R.J. Knize, Opt. Lett. \textbf{28} (19), 1814 (2003).} and report a precision value for the 6$P_{3/2}$ state of cesium. A single pulse ($\sim $nJ) from a modelocked Ti:Sapphire laser excites atoms in counterpropagating thermal beams to the 6$P_{3/2}$ state. A subsequent laser pulse is amplified using a regenerative amplifier to a few $\mu $J and is frequencydoubled, and ionizes atoms in the excited state. The ions are collected using a channel electron multiplier and counted. The measurement is repeated using excitation and detection pulses that are increasingly separated in time, allowing the decay from the excited state to be determined. Our analysis indicates a lifetime of 30.44~ns with a statistical uncertainty of 0.02~ns. We will discuss improvements in our apparatus and address the dominant systematic effects. These include (1) the effects of imperfect extinction ratio of the electrooptic modulators used for laser pulse selection; (2) the effects of atoms moving through spatially nonuniform laser beams; and (3) the effects of misalignment of the excitation and ionization laser beams. [Preview Abstract] 

K1.00095: Progress on single indium ion and single barium ion frequency references William Trimble, Jeff Sherman, Adam Kleczewski, Warren Nagourney, Norval Fortson Energy levels in laser cooled trapped ions are attractive as optical frequency standards because they can be made free of many external perturbations. We report continued development of single indium ion and barium ion rf PaulStraubel traps and laser cooling systems. In In$^+$, the forbidden ${^1}S_0 \leftrightarrow {^3}P_0$ transition at 237 nm has a quality factor of $10^{15}$ and is immune to DC quadratic Stark shifts. In Ba$^+$, the $\tau \sim 80$~s gives the electric dipole forbidden 2051 nm $6S_{1/2} \leftrightarrow 5D_{3/2}$ transition a quality factor of $10^{16}$. Further, by choosing the transition $6S_{1/2} (F=2, m=0) \leftrightarrow 5D_{3/2} (F' = 0, m' =0)$ transition in $^{137}$Ba$^+$ (I = 3/2), the first order DC quadrupole Stark shift and 2nd order Zeeman shits can be made to vanish. We present our latest experimental probes of these transitions using diode pumped solid state laser systems (a frequency quadrupled nonplanar ring oscillator Nd:YAG at 946 nm and a diode pumped Tm,Ho:YLF at 2 $\mu$m) stabilized to verticallymounted ULE reference cavities. [Preview Abstract] 

K1.00096: Laser spectroscopy with lithium atoms in an undergraduate lab Tory Carr, Yancey Sechrest, Scott Waitukaitis, Alex Cronin We present highlights from an undergraduate laboratory using 671 nm diode lasers to study spectra of lithium atoms. Faraday rotation spectra, the Hanle effect, atom beam deflection, and saturation absorption spectra are demonstrated. We also describe how the extended cavity diode lasers and heatpipe lithium vapor cells were constructed. [Preview Abstract] 

K1.00097: Molecular Conformation of Optically Active Five and Six MemberedRing Ketones Watheq AlBasheer, Richard Pagni, Robert Compton Conformational analysis of chiral five and six  membered  ring ketones will be presented. Electronic circular dichroism (CD) and vibrational circular dichroism (VCD) spectra for both $R$ and $S$ enantiomers of optically active carvone (C$_{10}$H$_{14}$O) exhibit marked temperature dependences. Theoretical calculations, using density functional theory (B3LYP with augccpVDZ basis set), show an equal magnitude but opposite \textit{sign} for the CD and VCD for the two conformers of each $R$ and $S$ enantiomer. The Temperature dependent circular dichroism (CD) measurements of $R$(+)3methylcyclopentanone $R$3MCP in 36 different common solvents is being employed to determine the conformers energy between the equatorial methyl and axial methyl of $R$3MCP and carvone. The results will be compared to the CD in the gas phase, solvent effect on optical rotation of $R$3MCP and carvone will be demonstrated and supported by DFT calculations. Temperature dependent vibrational Raman spectroscopy in the CH stretch region is used to study conformation over a wide range of temperature (15135 \r{ }C) and at liquid nitrogen temperature. Temperature dependent variations of CD and Raman spectra are shown to be a useful technique to study the conformer's populations and energy difference. [Preview Abstract] 

K1.00098: FiberBragggrating stabilized diode laser at 1450 nm locked to a high finesse buildup cavity. Thomas DeVore, Matthew Redshaw, Edmund Myers Using Dopplertuned fastbeam laser spectroscopy and a high finesse buildup cavity ($F\sim $60,000) excited by a 1319 nm Nd:YAG laser we previously measured the 1$s$2$s \quad ^{1}$S$_{0}$  1$s$2$p \quad ^{3}$P$_{1}$ intercombination interval in Si$^{12+}$ to be 7230.5(2) cm$^{1}$ [1]. The precision was limited by uncertainty in the (v/c $\sim $ 5{\%}) ion beam velocity. An order of magnitude higher precision would provide a clear test of calculations of QED contributions in twoelectron ions. We aim to attain this by alternately exciting the resonance with co and counterpropagating laser beams using a cavity that has highfinesse for both 1319 nm and 1450 nm. For the 1450 nm wavelength we are using fewhundred mW, fibercoupled, pump laser diodes that have been spliced to custom fiberBragggratings to achieve singlemode operation and greatly reduced linewidth [2]. The lock to the buildup cavity is achieved using the PoundDreverHall technique with feedback to the laser diode current and to a piezo that strains the fiber between the laser and the FBG. The assistance of A. Khademian and D. Shiner (Univ. North Texas) is gratefully acknowledged. [1] M. Redshaw and E.G. Myers, PRL \textbf{88} 023002 (2002). [2] A. Khademian and D. Shiner, BAPS \textbf{51}, 145 (2006). [Preview Abstract] 

K1.00099: ULTRACOLD MATTER II 

K1.00100: A Diode Laser System for the Trapping of Fermionic $^6$Li C. Welford, D. Dries, M. Junker, J. Hitchcock, Y.P. Chen, R.G. Hulet We have built an alldiode system for confining $^6$Li in a MOT. A single 45 mW Mitsubishi diode in an extended cavity is locked to the 2 $^2$S$_{1/2}$, F = $\frac{3}{2}$ $\leftrightarrow$ 2 $^2$P$_{3/2}$, F = $\frac{5}{2}$ transition (D2) and seeds a 45 mW slave which provides the trapping light. Two additional 45 mW masterslave pairs which are frequency offset locked to the first laser provide the repump (on the D1 transition) and Zeeman slowing light. This laser system has been added to our exisiting apparatus which now produces BECs of $^7$Li. Evaporation of the bosonic $^7$Li sympathetically cools the $^6$Li in a magnetic trap, prior to transfer to an optical trap/lattice. This system will allow us to simulate quantum manybody phenomena that arise in condensed matter systems. [Preview Abstract] 

K1.00101: Superfluorescence from LaserCooled Atoms E. Paradis, B. Barrett, A. Kumarakrishnan, R. Zhang, G. Raithel We have observed temporally resolved superfluorescence (SF) from samples of lasercooled Rubidium atoms. The atomic system was excited to the 5D level from the ground state by a twophoton process, involving excitation laser pulses tuned to the vicinity of the 5S5P and 5P5D transitions. We observe timedelayed signals on the 6P5S transition at 420nm. The delay time of these pulses $\sim $N$^{1}$, where N is the atom number. These time delays are much smaller than expected for the case of cascade fluorescence. Since N is significantly smaller than the threshold number for SF on this transition, our observations suggest that the 420nm emission is triggered by rapid deexcitation of the 5D level through SF at 5.2$\mu$m. If the shape of the trapped sample is changed from a sphere to a cigar, we observe that the signal changes from being isotropic to being strongly enhanced along the long axis of the sample. We also discuss the properties of the SF emission by varying the temporal sequence of the excitation pulses. [Preview Abstract] 

K1.00102: Experimental Progress in LaserCooling Molecules Michael Di Rosa, Alexei Tonyushkin At Los Alamos National Laboratory, we are studying a particular class of diatomics  the alkalineearth monohydrides ({\em e.g.} BeH and CaH)  that have Rydberg transitions similar to the $^2$$P_{1/2,\, 3/2} \leftarrow \, ^2$$S_{1/2}$ transitions of alkali atoms and appear suited to laser cooling. As a class, the $A\leftarrow X$ transitions of the alkalineearth monohydrides possess characteristics that are favorable for Dopplercooling, including a (nearly) diagonal FranckCondon array and good spectral isolation of the transitions that form the cooling cycle. We will show how a beam of such molecules can be laser cooled and report the status of our experiments for the particular case of CaH. [Preview Abstract] 

K1.00103: Development of a Quantum Gravity Gradiometer for Gravity Measurement from Space James Kellogg, Nan Yu, James Kohel, Rob Thompson, Dave Aveline, Erika D'Ambrosio, Lute Maleki Recent progress in cold atom interferometry has provided a new technique for sensitive inertial sensing. We are developing a mobile quantum gravity gradiometer for gravity field mapping using cold atom interferometers and employing component technologies suitable for a future flight instrument. We report on recent progress in the development of this gravity gradiometer, as well as results from related studies of coherence effects in atomwave interferometers. [Preview Abstract] 

K1.00104: Dynamics of OH in a magnetoelectrostatic trap Manuel Lara, Benjamin Lev, Brian Sawyer, Jun Ye, John L. Bohn OH molecules resulting from Stark deceleration have been recently confined in a magnetic quadrupole trap. An electric field can be simultaneously applied to the trap, significantly influencing its dynamics. We have modeled the potential energy that governs the dynamics of the molecules in such a ``magnetoelectrostatic'' trap, using a complete effective molecular Hamiltonian for OH. We find, however, that the resulting trapping potential can also be easily understood and even semiquantitativelly reproduced using simple classical models. We also discuss the trap lifetime due to nonadiabatic transitions to untrapped states, i.e., the analog in this trap of Majorana transitions in a quadrupole magnetic trap. [Preview Abstract] 

K1.00105: A new optical decelerator to make ultracold molecules Susumu Kuma, Daisuke Ando, Masaaki Tsubouchi, Takamasa Momose We propose a new method to decelerate molecules using a dipole force of intense IR radiation. We found that periodical switching of a standing wave in an IR cavity decelerate moleucles very efficiently. Numerical simulations showed large phase space areas of decelerated molecules by this technique. An experimental setup to make ultracold molecules from the room temperatures will be proposed. [Preview Abstract] 

K1.00106: Experimental Progress Towards the Development of Neutral Atom Quantum Computing Architecture Based on 2D Optical Lattices on a Chip Rajani Ayachitula, Andrew Morss, Greg Lafyatis, Katharina GillenChristandl Previously, we showed, theoretically, that optical lattices can be created above an optical waveguide by destructively interfering laser light in two different waveguide modes. [1] Single atoms can be tightly trapped at the nodes of a lattice and can serve as individually addressable qubits of a quantum memory. We have also examined moving the atoms within the lattice. We have studied ways to realize one and twoqubit gates. On the experimental side, we have developed and characterized optical waveguides suitable for making these optical lattices. We measure losses $\mathbin{\lower.3ex\hbox{$\buildrel<\over {\smash{\scriptstyle\sim}\vphantom{_x}}$}} $1db/cm for TE0 and TE1 modes. To address individual modes we couple light into the waveguide modes using gratings fabricated on the waveguide surface. We have observed $>$15{\%} coupling efficiency. Our initial scientific studies will characterize samples of cold atoms dropped onto the waveguide. We will discuss recent experimental progress. 1. Phys. Rev. A 70 032302 (2004) [Preview Abstract] 

K1.00107: BoseFermiHubbardModel in the limit of large fermionic hopping an effective theory Alexander Mering, Michael Fleischhauer We present calculations for the BoseFermiHubbard model in the limit of large fermionic hopping. Using the BornOppenheimer and the Markovapproximation leads to an effective hamiltonian for the bosons. This hamiltonian describes an infinite range extended BoseHubbard model with a long range densitydensity coupling which oscillates with a period that depends on the fermionic density. The resulting phase diagram consists of several different phases which will be analytically discussed and compared to numerical results obtained by exact diagonalization and DMRG methods. [Preview Abstract] 

K1.00108: Two bosonic dipoles under elongated confinement Krittika Kanjilal, Doerte Blume The behaviors of two particles under harmonic confinement strongly depend on the aspect ratio $\eta$, which is defined as the ratio between the trapping frequency along the $\rho$ and the $z$ directions. It has been shown that the properties of particles interacting through spherically symmetric potentials are, in the extreme limits of very large and very small $\eta$, well described by effective one and twodimensional Hamiltonian. This work considers two particles with anisotropic interactions confined in an elongated harmonic trap. Assuming that the dipole moments are aligned along the zaxis, we obtain the eigen spectrum of this system analytically and analyze how it changes as a function of $\eta$. To validate our analytical approach, we compare our results with the eigen spectrum obtained numerically for a shortrange shapedependent potential. [Preview Abstract] 

K1.00109: Time Evolution of Freely Expanded BoseEinstein Condensates Containing Small Numbers of Atoms DianJiun Han, DeSheng Hong, K.H. Huang, TsinFu Jiang We investigate the time evolution of freely expanded BoseEinstein condensates by measuring their aspect ratios at different times after releasing from a magnetic trap. In these measurements, the condensates contain no more than 9000 $^{87}$Rb atoms. By varying the trapping frequency and atom number, we measure the condensate aspect ratios at different expansion times in free space. We compare our measurements with that calculated from the ThomasFermi model and a direct numerical solution. Under our trapping condition, the data of the time dependent aspect ratios of the freely expanded condensates reasonably agree with the numerical calculations, but show clear deviation from the predictions by the ThomasFermi model when the atom number in the condensates is small. [Preview Abstract] 

K1.00110: Vortex formation during the growth of BoseEinstein condensates Chad Weiler, Tyler Neely, David Scherer, Brian Anderson We experimentally study of the growth of BoseEinstein condensates in harmonic trapping potentials with laserinduced perturbations to the potential well. We find that some time independent perturbations can significantly impact the growth process and final state of the BEC. In particular, in numerical simulations and our experiments, we have observed the generation of vortices and vortexantivortex pairs as a result of creating BECs in perturbed potentials. We will describe the results of our ongoing and completed experiments (D.R. Scherer, C.N. Weiler, T.W. Neely, B.P. Anderson, condmat/0610187, to be published in Phys. Rev. Lett.). [Preview Abstract] 

K1.00111: NextOrder Analytic Wave Function for Correlated Confined Quantum Systems; Application to BEC W. Blake Laing, Martin Dunn, Derrick R. Toth, Deborah K. Watson We have constructed the nextorder correlated $N$body wave function for an isotropic confined quantum system using a dimensional perturbation theory (DPT) approach. This additional perturbative order represents a significant advancement in our largescale project of analytically describing beyondmeanfield effects in $N$body systems using DPT. To solve this problem, we assemble a number of analytic building blocks within the DPT framework (such as ``symmetry coordinates'', coupling products of irreducible representations, and a novel graphtheoretical technique). This method is wellsuited for systems with ``tunable'' interactions because it makes no assumptions concerning the number of particles or the strength of interparticle interactions. As an application, we report observable results for the density profile, excitation frequencies, and ground state energy of a fully correlated BEC in a harmonic trap. [Preview Abstract] 

K1.00112: Spinor matter waves in optical lattices Tristram Alexander, Beata DabrowskaWuster, Elena Ostrovskaya, Yuri Kivshar We study, within the framework of the GrossPitaevskii model, nonlinear properties exhibited by a spinor F = 1 BoseEinstein condensate confined in a onedimensional optical lattice. We show that the lattice modifies dynamical stability properties of both ferromagnetic and polar condensates with repulsive atomic interactions. This leads to modulational instability of threecomponent Bloch states of the spinor BEC at the edge of the first Brillouin zone regardless of the properties of the spinor ground state (ferromagnetic or polar). As a result, both ferromagnetic and polartype nonlinearly localized states can coexist within the gap of the matter wave bandgap spectrum in the form of vector gap solitons with a small number of atoms and selftrapped gap waves containing a large number of atoms. We explore the variety of spatially localized states in the lattice potential and show that, in general, the localization properties and nonequilibrium dynamics of the spinor BEC in the lattice cannot be captured by the singlemode approximation, usually employed for the meanfield description of the spinor matter waves. [Preview Abstract] 

K1.00113: Feshbachstimulated Raman photoproduction of a BoseEinstein condensate of singlet molecules Matthew Fenty, Danielle Savage, Matt Mackie We theoretically examine the formation of a quantum degenerate gas of stable singlet molecules via Feshbachstimulated Raman photoproduction, or freeboundboundboundbound transitions from an atomic to a singlet molecular BoseEinstein condensate. In particular, a magnetic field tuned near a Feshbach resonance initiates collective conversion from an atomic condensate to a triplet molecular condensate, which is then converted by threelaser stimulated Raman adiabatic passage (STIRAP) to a stable singlet molecular condensate. Although population of the target singlet state is nearunit efficient, the population of an intermediate state is significant ($\sim10^{3}$), and large boundbound Rabi couplings ($\sim10$~GHz) are required to avoid losses. [Preview Abstract] 

K1.00114: Effects of resonant coupling on the formation of ultracold $^{85}$Rb$_2$ molecules H.K. Pechkis, D. Wang, Y. Huang, E.E. Eyler, P.L. Gould, W.C. Stwalley, Christiane P. Koch We have studied the effect of resonant electronic state coupling on the formation of ultracold groundstate $^{85}$Rb$_2 $. The ultracold Rb$_2$ are formed by photoassociation (PA) to the $0_u^+$ state converging to the $5S+5P_{1/2}$ limit, followed by radiative decay into high vibrational levels of the ground state, $X~^1\Sigma_g^+$. The populations of high$v$ levels of the $X$ state are monitored by resonanceenhanced two photon ionization through the $2~^1\Sigma_u^+$ state. We find that the populations of vibrational levels $v"$=112116 are far larger than can be accounted for by the FrankCondon factors for $0_u^+ \leftarrow X~^1\Sigma_g^+$ transitions. Further, the groundstate molecule population exhibits oscillatory behavior as the PA laser is tuned through a succession of $0_u^+$ state vibrational levels. Both of these effects explained by a new calculation of transition amplitudes that includes the resonant character of the spinorbit coupling of the two $0_u^+$ states converging to the $5P_{1/2}$ and $5P_{3/2}$ limits. The resulting enhancement of more deeply bound groundstate molecule formation will be useful for future experiments on ultracold molecules. We also present the progress toward forming $^{85}$Rb$_2$ by photoassociation in an optical dipole trap using a CO$_2$ laser. This work is supported by the NSF. [Preview Abstract] 

K1.00115: Longrange Efimov states B.D. Esry, J.P. D'Incao We have identified a new class of Efimov states that appear in heteronuclear threebody systems where both intra and interspecies interactions are resonant. Besides their peculiar geometry, we speculate that such states should be truly universal. That is, their properties should only depend on the scattering lengths. These states' longrange character forbids them to see the details of the interatomic interactions, which normally introduces an extra parameter into expressions relating to ``ordinary'' Efimov states. In the context of ultracold gases with tunable interactions, we thus believe that it is possible to predict precisely when such states should appear. Consequently, the observation of a single state would be enough to demonstrate the Efimov effect. [Preview Abstract] 

K1.00116: Analysis of strongly interacting fewbody systems under external confinement Javier von Stecher, Jose P. D'Incao, Chris H. Greene We investigate the properties of three and fourbody systems under external confinement interacting through a short range model potential. Using a correlated gaussian basis set, we study the spectra as a function of the twobody scattering length for fermionic and bosonic systems. From these results we can extract the main properties of the hyperspherical effective potentials, which in turn dictates the main collisional aspects for such systems. We also investigate the existence of weakly bound fourbody states and their relation with the Efimov physics. [Preview Abstract] 

K1.00117: Production and Trapping of Ultracold Polar Molecules Nathan Gilfoy, Eric Hudson, Jeremy Sage, Sunil Sainis, David DeMille Recently we have demonstrated the production of a sample of ultracold, polar RbCs molecules in their absolute vibronic ground state. The sample has a translational temperature of ~100 $\mu$K and a narrow distribution of rotational states. The molecules are initially formed from lasercooled $^{85}$Rb and $^{133}$Cs atoms via photoassociation, resulting in shortlived, vibronically excited RbCs molecules. A fraction of these excited molecules subsequently spontaneously decay to ground electronic states, populating many excited vibrational levels. We then transfer the population of one of these levels, a$^3\Sigma^+$ (v = 37), to the absolute vibronic ground state via a pumpdump scheme. We discuss progress toward observing strong, anisotropic collisions between these molecules through trapping them using a quasielectrostatic trap (QUEST). We will also discuss our progress in implementing a Stimulated Adiabatic Raman Passage scheme to improve the transfer process to the vibronic ground state. [Preview Abstract] 

K1.00118: Experimental progress towards investigation of ultracold KCs molecules Daniel Barker, Myrrha Andersen, Joseph Porembski, Marin Pichler We report on progress towards simultaneous cooling and trapping of K and Cs atoms with the objective to produce ultracold KCs molecules, for spectral investigation. Our systems consists of separate lasers for cooling and repumping transitions for both species and a simple locking scheme. We present the photoassociation and resonant multiphoton detection schemes, and discuss possible applications. [Preview Abstract] 

K1.00119: Progress toward measuring fast atomic recombination in ultracold plasma Michael Lim, Lucas Willis We report on progress toward measuring the timedependent distribution of atomic energy levels populated by recombination and collisions in ultracold plasma. The plasma is produced by direct photoionization of rubidium atoms in a magnetooptical trap. Our primary goal is to measure the changing Rydberg atom distribution in the first microsecond after plasma creation. Although predictions have been made for system behavior in this interval, this type of measurement has been elusive. Our apparatus features fast deflector plates to prevent saturation of the multichannel plate detector, which is one of the main technical obstacles in this effort. [Preview Abstract] 

K1.00120: AllOptical Production of Degenerate Fermi Gas toward Optical Lattice Experiments Yasuhisa Inada, Taizo Miyato, Shuta Nakajima, Makoto KuwataGonokami, Masahito Ueda, Takashi Mukaiyama Atomic Fermi gases with tunable interactions offer possibilities to study strongly correlated systems, and have attracted much interest experimentally and theoretically. Fermionic atoms in optical lattices are analogous to electrons in crystals and are expected to form quantum phases, which may allow us to more deeply understand superfluidity and magnetism. In this poster, we report on the alloptical production of a degenerate gas of ${}^{6}$Li. To eliminate bulky coils for a magnetic trap and have a better optical access for optical lattice experiments, we captured and cooled atoms in an all optical way. We set up a cavity to build up the intensity of a 1064 nm laser for the optical trap, to get 1 mK in trap depth with a beam waist of 260 $\mu$m. This cavityenhanced optical trap enabled us to recapture 15 \% of atoms in the MOT. We then transferred the atoms into a focused beam dipole trap and evaporatively cooled the atoms to reach $T/T_{F} \sim 0.1$ with $4 \times 10^{5}$ atoms. [Preview Abstract] 

K1.00121: Phase diagram of a polarized Fermi gas in the BECBCS crossover Y.A. Liao, W. Li, G.B. Partridge, R.G. Hulet The phase diagram of a polarized Fermi gas in the BECBCS crossover is rich and largely unknown. We optically trap $^6$Li atoms with unequal population in the lowest two spin states.\footnote{G. B. Partridge {\it et al.}, {\it Science} {\bf 311}, 503 (2006).}$^{,}$\footnote{G. B. Partridge {\it et al.}, {\it Phys. Rev. Lett.} {\bf 97}, 190407 (2006).} At the lowest temperatures in the unitarity regime, we observe phase separation between a paired superfluid core surrounded by the unpaired atoms. At higher temperatures but below the superfluid transition temperature, our data is consistent with a polarized superfluid state (Sarma phase). The Sarma phase is expected to dominate at zero temperature on the BEC side of the Feshbach resonance, while on the BCS side the gas is either phase separated (low P and T) or a normal fluid. We present our experimental mapping of the phase diagram as a function of P, T, and interaction. [Preview Abstract] 
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