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arXiv · 1604.05900

Thermal and quantum fluctuations of confined Bose-Einstein condensate beyond the Bogoliubov approximation

Y. Nakamura·T. Kawaguchi·Y. Torii·Y. Yamanaka
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Abstract

The formulation for zero mode of a Bose-Einstein condensate beyond the Bogoliubov approximation at zero temperature [Y.Nakamura et al., Phys. Rev. A 89, 013613 (2014)] is extended to finite temperature. Both thermal and quantum fluctuations are considered in a manner consistent with a concept of spontaneous symmetry breakdown for a finite-size system. Therefore, we need a proper treatment of the zero mode operators, which invoke non-trivial enhancements in depletion condensate and thermodynamical quantities such as the specific heat. The enhancements are visible in the weak interaction case. Our approach reproduces the results of a homogeneous system in the Bogoliubov approximation in a large particle number limit.

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Y. Nakamura, T. Kawaguchi, Y. Torii, Y. Yamanaka. 2016-04-20. Thermal and quantum fluctuations of confined Bose-Einstein condensate beyond the Bogoliubov approximation. https://doi.org/10.1016/j.aop.2016.12.020

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