Bulletin of the American Physical Society
2006 37th Meeting of the Division of Atomic, Molecular and Optical Physics
Tuesday–Saturday, May 16–20, 2006; Knoxville, TN
Session S1: Coherent Spinor Dynamics in Ultracold Gases |
Hide Abstracts |
Chair: Presiding person to be selected Room: Knoxville Convention Center Lecture Hall |
Friday, May 19, 2006 8:00AM - 8:36AM |
S1.00001: Coherent spinor dynamics in all-optical spin-1 condensates Invited Speaker: All-optical approaches to BEC that we have developed offer considerable flexibility and speed compared to magnetic trap approaches. Additionally, they are ideally suited to the study of spinor condensates, which are multi-component BEC's with internal spin degrees of freedom described by a vector order parameter. The delicate interplay of the different magnetic quantum gases yields a rich variety of phenomenon including Josephson oscillations and spin domain formation. I will describe our observation of coherent spin changing collisions in a spin-1 rubiudium-87 condensate, which provides convincing validation of the mean-field theoretical treatment of the system dynamics. [Preview Abstract] |
Friday, May 19, 2006 8:36AM - 9:12AM |
S1.00002: Resonance spin dynamics in ultracold gases Invited Speaker: Collective dynamical effects and in particular coherent interactions in spinor Bose Einstein condensates offer new fundamental insights into a new class of magnetic phenomena at ultralow energies, which connect conventional magnetism and coherent spin dynamics. Concentrating on $^{87}$Rb spinor condensates we present experimental observations of a magnetically tuned resonance phenomenon in the spin mixing dynamics in a $F=2$ system. We analyze general features like quadratic Zeeman dephasing and its influence on coherent spin mixing processes and propose an extension of the resonance concept to higher spin systems in the framework of four wave mixing. Furthermore we discuss experimental signatures of the transition from coherent spinor oscillations to thermal equilibration, which is marked by dephasing and decoherence of the spinor order parameter. An outlook on future work towards spinor Bose-Einstein condensates on a triangular optical lattice will be given. [Preview Abstract] |
Friday, May 19, 2006 9:12AM - 9:48AM |
S1.00003: Dipolar spinor condensate: a novel magnetic anisotropic superfluid Invited Speaker: Dipolar interactions play crucial roles in quantum magnetism. Recent experimental breakthrough of a chromium condensate (with ground state magnetic dipole moment as large as 6 Bohr magneton) rekindles great interest in dipolar effects in atomic Bose-Einstein condensates. Here we focus on the ground state structure of a dipolar spin-1 condensate. We show that the interplay between the short-range isotropic collisional interactions and the long-range anisotropic dipolar interactions gives rise to an extremely rich phase diagram, characterized by intricate spontaneous magnetic ordering and spin textures. These textures arise as a result of the dipolar-induced coupling between the spin and orbital degrees of freedom. The tunability of the effective dipolar interaction in atomic gases provides a new set of control knobs on condensates, and access to different magnetic phases can be achieved by modifying the trapping geometry. The feasibility of observing these dipolar-induced phases in alkali spinor condensates is analyzed. [Preview Abstract] |
Friday, May 19, 2006 9:48AM - 10:24AM |
S1.00004: Spontaneous Symmetry Breaking in a Ferromagnetic Spinor Condensate Invited Speaker: Spinor condensates are multicomponent quantum fluids with a spin degree of freedom and are predicted to exhibit a variety of phenomena including complex spin textures, highly correlated spin states and domain formation. The talk will present a brief overview of spinor condensates and a recently demonstrated technique of nondestructive imaging of the magnetization of spinors. This technique enables the in situ study of spinor dynamics such as the nucleation and growth of spin textures. I will elaborate on recent observations of spontaneous symmetry breaking in a F=1 Rb spinor condensate as it is quenched past a ``polar'' to ferromagnetic quantum phase transition. During this process, phase contrast images reveal the spontaneous formation of ferromagnetic domains with a characteristic length scale of 6 microns, much smaller than the size of the condensate. Concurrent with the formation of these domains, we also observe the spontaneous formation of topological defects which we characterize as singly charged spin vortices. [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