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 B2: Focus Session: Dynamic and Out-of-Equilibrium Phenomena in Cold Atoms |
Hide Abstracts |
Chair: D. Feder, University of Calgary Room: TELUS Convention Centre Macleod D |
Wednesday, June 6, 2007 10:30AM - 11:06AM |
B2.00001: Observation of a dimensional crossover from 1D to 3D gases Invited Speaker: A 1D gas with $\delta $-fn interactions is an integrable many-body system, which means, among other things, that it does not thermalize after it is prepared out of equilibrium. We recently demonstrated this experimentally using a quantum Newton's cradle, an array of out-of-equilibrium 1D Bose gases. When we reduce the depth of the 2D optical lattice that makes the 1D systems, the mapping onto an integrable system is compromised. We see the atoms begin to thermalize, at a rate that depends exponentially on the lattice depth, with no apparent threshold. How energy is shared among dimensions after the system reaches equilibrium also depends on the lattice depth, and varies continuously from all the energy being in one dimension to equipartition of energy among dimensions. We will also describe other experimental handles on integrability. This work was performed with Toshiya Kinoshita and Trevor Wenger. [Preview Abstract] |
Wednesday, June 6, 2007 11:06AM - 11:42AM |
B2.00002: Quantum gases out of balance. Invited Speaker: The trapping of an ultracold gas of atoms in the periodic potential of a three-dimensional optical lattice is a simple experimental concept. However, the physics accessible with such a system stretches out to a unique variety of directions, including quantum phase transitions, low-dimensional systems, Hubbard models and the physics of few particle systems. In particular, dynamic and non-equilibrium phenomena have become experimentally accessible. In this talk I will report on experiments investigating transport and non-equilibrium phenomena in quantum gases. [Preview Abstract] |
Wednesday, June 6, 2007 11:42AM - 11:54AM |
B2.00003: Cold matter and short laser pulses: creating cold molecules and probing pair correlations in condensates. Francoise Masnou-Seeuws, Jordi Mur-Petit, Eliane Luc-Koenig We have analyzed the formation of Rb$_2$ molecules with short photoassociation pulses applied to a cold $^{85}$Rb sample. The laser field couples a continuum level of the ground electronic state X$^1\Sigma_{\textrm{g}}^+$ with bound levels in the 0$_{\textrm{u}}^+$(5S+5P$_{1/2}$) and 0$_{\textrm{u}}^+$(5S+5P$_{3/2}$) vibrational series. The non-adiabatic coupling between the two excited channels induces time-dependent beatings in their populations [1]. We propose to take advantage of these oscillations either to probe the photoassociation process via a photoionization pulse, or to optimize the stabilization step into deep levels of the ground state [1]. Presently, in collaboration with the experimental group of Chris Westbrook in Orsay, we are extending our dynamical calculations to study the time-dependent correlations that the photoassociation laser triggers in an atomic condensate [2], and how they can be experimentally measured, {\em e.\ g.} in cold samples of metastable helium [3]. \newline {\bf References:} \noindent[1] J.\ Mur-Petit, E.Luc-Koenig, and F.\ Masnou-Seeuws, arXiv:physics/0612143. \noindent [2] P. Naidon and F. Masnou-Seeuws,{\em Phys. Rev. A} {\bf 73}, 043611 (2006).\noindent [3] M. Schellekens {\em et al.},{\em Science} {\bf 310}, 648 (2005). [Preview Abstract] |
Wednesday, June 6, 2007 11:54AM - 12:06PM |
B2.00004: Spontaneous symmetry breaking in parametrically driven atomic trap and observation of its critical properties. Myoung-Sun Heo, Yonghee Kim, Wonho Jhe, Kihwan Kim, Heung-Ryoul Noh While critical phenomena in equilibrium systems has been well established both in theory and in experiment, experimental studies in non-equilibrium or far-from-equilibrium systems still lack of quantitative investigation and remain as challenging subjects. Recently we have reported spontaneous symmetry-breaking(SSB) in nonequilibrium atomic system produced by parametrically exciting Magneto-optical trap. This critical phenomena is considered very unique in that it has similarities with other kinds of systems such as globally coupled Ising system and Glauber spin system. Hence we have measured critical exponents relevant to this phase transition, with respect to the control parameter, the size of the system or the total number of atoms. We also have observed the occurrence of SSB as the temperature is changed by illuminating a resonant laser light. In addition as in the other researches on Glauber spin, the spectral response to external field has been investigated. [Preview Abstract] |
Wednesday, June 6, 2007 12:06PM - 12:18PM |
B2.00005: Time-dependent electromagnetic wave dynamics in ultracold, high-density Rb vapor S. Balik, J. Mills, C.I. Sukenik, M.D. Havey, I.M. Sokolov, D.V. Kupriyanov Recent experiments and theoretical results on Anderson localization of light in condensed samples show that diffusive transport is strongly suppressed and that a regime of anomalous diffusion develops dynamically. Proximity of the light localization threshold can be detected through time evolution of either forward or diffusely scattered light. We report in this paper recent measurements on time-dependent light scattering in the spectral vicinity of the F = 1 $\rightarrow$ F$'$ = 0 optical transition in dense, ultracold atomic $^{87}Rb$ samples formed in an optical dipole trap. For the $\sim$ $10^{14}$ $atoms/cm{^3}$ density of these samples, the Ioffe-Regel criterion k\emph{l} $\sim$ 0.8, indicating that localization effects should be evident. Theoretical results on spectral variations of the total scattering cross section in the strong localization regime are also presented. [Preview Abstract] |
Wednesday, June 6, 2007 12:18PM - 12:30PM |
B2.00006: Collective self-focusing and atom-optical solitons William Williams, Mark Saffman We describe collective atom-optical solitons and modulational instability which appear due to mutual self-focusing of light and cold atoms. It is normally impossible to achieve simultaneous focusing since a two-level atom gives self- focusing of light for blue detuning, whereas the dipole potential is attractive for red detuning. Due to saturation effects self-focusing occurs with an attractive dipole potential under conditions of red detuning. We present experimental signatures of this effect observed using cold Cs atoms in a MOT. [Preview Abstract] |
Wednesday, June 6, 2007 12:30PM - 12:42PM |
B2.00007: Non-monotonicity in the quantum-classical transition: Chaos induced by quantum effects Arjendu Pattanayak, Arie Kapulkin The transition from classical to quantum behavior for chaotic systems is understood to be accompanied by the suppression of chaotic effects as the relative size of $\hbar$ is increased. We show evidence to the contrary in the behavior of the quantum trajectory dynamics of a dissipative quantum chaotic system, the double-well Duffing oscillator. The classical limit in the case considered has regular behavior, but as the effective $\hbar$ is increased we see chaotic behavior. This chaos then disappears deeper into the quantum regime, which means that the quantum-classical transition in this case is non-monotonic in $\hbar$. [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