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Kicked Bose-Hubbard systems and kicked tops -- destruction and stimulation of tunneling

M P Strzys·E M Graefe·H J Korsch
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Abstract

In a two-mode approximation, Bose-Einstein condensates (BEC) in a double-well potential can be described by a many particle Hamiltonian of Bose-Hubbard type. We focus on such a BEC whose interatomic interaction strength is modulated periodically by $δ$-kicks which represents a realization of a kicked top. In the (classical) mean-field approximation it provides a rich mixed phase space dynamics with regular and chaotic regions. By increasing the kick-strength a bifurcation leads to the appearance of self-trapping states localized on regular islands. This self-trapping is also found for the many particle system, however in general suppressed by coherent many particle tunneling oscillations. The tunneling time can be calculated from the quasi-energy splitting of the corresponding Floquet states. By varying the kick-strength these quasi-energy levels undergo both avoided and even actual crossings. Therefore stimulation or complete destruction of tunneling can be observed for this many particle system.

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M P Strzys, E M Graefe, H J Korsch. 2007-10-01. Kicked Bose-Hubbard systems and kicked tops -- destruction and stimulation of tunneling. https://doi.org/10.1088/1367-2630%2F10%2F1%2F013024

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