Bulletin of the American Physical Society
40th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics
Volume 54, Number 7
Tuesday–Saturday, May 19–23, 2009; Charlottesville, Virginia
Session L1: Focus Session: AMO Realizations of Condensed Matter Systems |
Hide Abstracts |
Chair: Han Pu, Rice University Room: Chemistry Hall 402 |
Thursday, May 21, 2009 2:00PM - 2:12PM |
L1.00001: Quantum Simulation of Magnetism with Ytterbium Ions Ming-Shien Chang, Kihwan Kim, Simcha Korenblit, Kazi Islam, Christopher Monroe An array of cold trapped ions has recently been identified as a promising physical implementation of a quantum simulator [1,2], thanks to the tunable long range couplings between ions and its advanced status on quantum computation applications. In particular, ions coupled by tightly bound transverse normal modes allows more efficient cooling and wide tunability of the effective spin-spin couplings. We will report our most recent simulation results of quantum spin Hamiltonians with few trapped ytterbium ions, coupled by transverse modes. We will also discuss on how this may be scaled up to a much larger number of spins with anharmonic traps and using multiple transverse modes. This work is supported by the DARPA OLE Program under ARO contract, IARPA under ARO contract, the NSF PIF Program, and the NSF Physics Frontier Center at JQI. [1] D. Porras and J. I. Cirac, Phys. Rev. Lett. 92, 207901 (2004) [2] A. Friedenauer et al., Nat. Phys. 4, 757 (2008) [Preview Abstract] |
Thursday, May 21, 2009 2:12PM - 2:24PM |
L1.00002: Towards Simulating Charged Particles in a Magnetic Field with a Bose-Einstein Condensate Using Light-induced Vector potentials Yu-Ju Lin, Robert Compton, Abigail Perry, William Phillips, Trey Porto, Ian Spielman We experimentally study light-induced gauge potentials in a $^{87}$Rb Bose-Einstein condensate. The atoms, dressed by a two-photon Raman coupling between the three $F=1$ hyperfine ground states, acquire a controllable quasi-momentum (static in the lab frame). We adiabatically load the atoms into the lowest energy dressed state, whose measured spin and momentum decomposition agrees quantitatively with a simple single- particle model. The effective Hamiltonian of these neutral atoms is like that of charged particles in a uniform magnetic vector potential, whose magnitude is set by the strength and detuning of Raman coupling. This technique can be extended to non-uniform vector potentials, giving non-zero effective magnetic fields. Current efforts are focused on eliminating heating of the dressed state from technical noise in the relative phase between two driving Raman beams, which limits the lifetime of the dressed state. This will then allow the observation of vortex nucleation into the condensate, signature of an effective magnetic field, upon addition of a detuning gradient. [Preview Abstract] |
Thursday, May 21, 2009 2:24PM - 2:36PM |
L1.00003: Suppression of the critical temperature for superfluidity near the Mott transition: validating a quantum simulator S. Trotzky, U. Schnorrberger, J. Thompson, I. Bloch, L. Pollet, N. Prokof'ev, B. Svistunov, F. Gerbier, M. Troyer Ultracold atoms in optical lattices have proven to be controllable, tunable and clean implementations of strongly interacting many-body systems. The large overlap of reachable Hamiltonians with condensed matter physics opens the possibility to use them as quantum simulators. A crucial step towards this goal is the validation of the experimental measurement for representative benchmark problems which are in reach of current numerical methods. We present the first ab-initio comparison between experiments and quantum Monte Carlo simulations for a large scale Bose gas (up to $N ~ 3\times10^5$) in an optical lattice potential. Using the simulation data to validate each step in the evaluation of the experiment, we are able to measure the finite temperature phase diagram of the system. We directly observe the suppression of the critical temperature $T_c$ for condensation upon approaching the Mott transition. Here, we rely on the sudden appearance of sharp interference peaks, signalling the onset of long range phase coherence as the temperature is decreased. This approach has been questioned lately and we demonstrate, how it can lead to a reliable estimate of $T_c$ by evaluating both the weight and width of the peaks. [Preview Abstract] |
Thursday, May 21, 2009 2:36PM - 3:06PM |
L1.00004: Strong Correlation Condensed Matter Physics in Cold Atom Optical Lattices Invited Speaker: I will discuss a few specific examples of non-trivial strong correlation phenomena from condensed matter theory considerations being studied on cold atom optical lattices, involving both bosons and fermions as well as boson-fermion mixtures. Some of the theoretical problems to be discussed in this talk are the quantum phase diagram of the bosonic Hubbard model in the presence of fermions, the possibility of observing a super-solid phase in the bosonic Hubbard model, the quantum phase diagram of multi-component density-imbalanced fermionic systems (i.e. FFLO or not), and exotic quantum order in optical lattices (e.g. d-Mott state, spin liquid, and topological states of matter). I will describe the experimental conditions necessary for observing strong correlation phenomena in cold atom optical lattices. [Preview Abstract] |
Thursday, May 21, 2009 3:06PM - 3:18PM |
L1.00005: Mesoscopic Transport with Ultracold Atoms Kunal Das, Seth Aubin We propose an experimental scheme to simulate mesocopic transport experiments with ultracold atoms on microtraps that would allow study of transport features not easily availabe in solid state electron-based systems, including, the effects of quantum statistics and the nonlinear effects of interactions of variable strengths. We illustrate with an application to a transport phenomenon called quantum pumping, a subject of much theoretical study in the context of solid state mesoscopic systems, but with no concrete and unambiguous experimental demonstration. We show that it can be implemented with cold atoms in a microchip with greater facility. Tests of this mechanism have strong applications value leading to improved control for charge and spin currents in nano-circuits. In addition, it has fundamental science implications since quantum pumps display geometric behavior, resonance transmission features, and in certain cases operate purely by quantum interference. [Preview Abstract] |
Thursday, May 21, 2009 3:18PM - 3:30PM |
L1.00006: Seeing Superfluids through Bose Glasses: Effects of Disorder on Condensates Scott E. Pollack, D. Dries, R. G. Hulet We probe the ground state of a disordered optical potential with a quasi-1D $^7$Li Bose-Einstein condensate (BEC). Competition between the tunable interatomic interactions and the effects of disorder result in a smooth transition from a superfluid at weak disorder to an insulating Bose glass state at strong disorder, characterized by density fragmentation and loss of global phase coherence. The location of this crossover in disorder strength varies with interatomic interactions, which are tuned from strongly repulsive, through zero, to weakly attractive interactions where the gas is predicted to populate single-atom states forming a Lifshits glass. We also report our investigations of expanding weakly interacting condensates in the presence of disorder and discuss the implications of these quantum glass states in the context of Anderson localization. [Preview Abstract] |
Thursday, May 21, 2009 3:30PM - 4:00PM |
L1.00007: Transport Measurements in the Disordered Bose-Hubbard Model Invited Speaker: We experimentally realize the disordered Bose-Hubbard model by introducing fine-grained disorder to ultra-cold atoms confined in an optical lattice. Transport measurements reveal that the equivalent of resistivity is unaffected in the quantum critical regime if the disorder strength is less than or comparable to the Hubbard interaction energy $U$. For extreme disorder, i.e., much greater than $U$, we observe a disorder-induced superfluid-to-insulator transition. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700