Orbital Josephson effect and interactions in driven atom condensates on a ring



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Sols Lucía, Fernando and Heimsoth, M. and Creffield, Charles E. and Carr, L.D. (2012) Orbital Josephson effect and interactions in driven atom condensates on a ring. New Journal of Physics, 14 . ISSN 1367-2630

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Official URL: http://dx.doi.org/10.1088/1367-2630/14/7/075023


In a system of ac-driven condensed bosons we study a new type of Josephson effect occurring between states sharing the same region of space and the same internal atom structure. We first develop a technique to calculate the long-time dynamics of a driven interacting many body system. For resonant frequencies, this dynamics can be shown to derive from an effective time-independent Hamiltonian which is expressed in terms of standard creation and annihilation operators. Within the subspace of resonant states, and if the undriven states are plane waves, a locally repulsive interaction between bosons translates into an effective attraction. We apply the method to study the effect of interactions on the coherent ratchet current of an asymmetrically driven boson system. We find a wealth of dynamical regimes which includes Rabi oscillations, self trapping and chaotic behavior. In the latter case, a full many-body calculation deviates from the mean-field results by predicting large quantum fluctuations of the relative particle number.

Item Type:Article
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© IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
We thank Justin Anderson and Christopher Gaul for useful discussions. We also acknowledge support from the Spanish MINECO through grant number FIS2010-21372 and the Ramón y Cajal program (CEC), the Comunidad de Madrid through Grant Microseres, the Heidelberg Center for Quantum Dynamics and the US National Science Foundation.

Uncontrolled Keywords:Bose-Einstein Condensate, T,T Method
Subjects:Sciences > Physics > Materials
ID Code:26488
Deposited On:05 Aug 2014 09:54
Last Modified:21 Jun 2022 17:15

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