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arXiv · 0902.3351

Dynamics of a many-particle Landau-Zener model: inverse sweep

A. P. Itin·P. Törmä
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Abstract

We consider dynamics of a slowly time-dependent Dicke model, which represents a many-body generalization of the Landau-Zener model. In particular, the model describes narrow Feshbach resonance passage in an ultracold gas of Fermi atoms. Adiabaticity is destroyed when a parameter crosses a critical value, even at very slow sweeping rates of a parameter. The dynamics crucially depends on direction of the sweep. We apply our recent analysis [A.P. Itin, P. Torma, arXiv:0901.4778v1] to the "inverse" sweep through the resonance, corresponding (in a context of Feshbach resonance passage) to dissociation of molecules. On a level of the mean-field approximation, the dynamics is equivalent to a molecular condensate formation from Bose atoms within a two-mode model. Mapping the system to a Painlevé equation allows us to calculate deviation from adiabaticity at very slow sweeps analytically.

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A. P. Itin, P. Törmä. 2009-02-19. Dynamics of a many-particle Landau-Zener model: inverse sweep. https://doi.org/10.1103/physreva.79.055602

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