Density Matrix of a Bose--Einstein Condensate: Steady--State versus Mean--Field Approach

S. J. Wang; M. C. Nemes; A. N. Salgueiro; H. A. Weidenmüller

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Density Matrix of a Bose--Einstein Condensate: Steady--State versus Mean--Field Approach

S. J. Wang·M. C. Nemes·A. N. Salgueiro·H. A. Weidenmüller

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Abstract

We compare the equilibrium solution for the condensate obtained in the mean--field approximation to the master equation for sympathetic cooling with the one obtained by Scully for a system in contact with a heat bath with the help of an analogy with the laser. While the mean--field approach yields analytical formulas for the approach towards equilibrium and for the equilibrium solution, it neglects the correlations between occupation numbers of different single--particle states which are approximately kept in Scully's approach. Such neglect is admissible as long as the fraction of Bosons in the condensate does not exceed a few percent or so.

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S. J. Wang, M. C. Nemes, A. N. Salgueiro, H. A. Weidenmüller. 2001-12-07. Density Matrix of a Bose--Einstein Condensate: Steady--State versus Mean--Field Approach. https://arxiv.org/abs/cond-mat/0111413

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