Low-dimensional Bose gases

U. Al Khawaja; J. O. Andersen; N. P. Proukakis; H. T. C Stoof

doi:10.1103/physreva.66.013615

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arXiv · cond-mat/0202085

Low-dimensional Bose gases

U. Al Khawaja·J. O. Andersen·N. P. Proukakis·H. T. C Stoof

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Abstract

We present an improved many-body T-matrix theory for partially Bose-Einstein condensed atomic gases by treating the phase fluctuations exactly. The resulting mean-field theory is valid in arbitrary dimensions and able to describe the low-temperature crossover between three, two and one-dimensional Bose gases. When applied to a degenerate two-dimensional atomic hydrogen gas, we obtain a reduction of the three-body recombination rate which compares favorably with experiment. Supplementing the mean-field theory with a renormalization-group approach to treat the critical fluctuations, we also incorporate into the theory the Kosterlitz-Thouless transition that occurs in a homogeneous Bose gas in two dimensions. In particular, we calculate the critical conditions for the Kosterlitz-Thouless phase transition as a function of the microscopic parameters of the theory. The proposed theory is further applied to a trapped one-dimensional Bose gas, where we find good agreement with exact numerical results obtained by solving a nonlinear Langevin field equation.

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U. Al Khawaja, J. O. Andersen, N. P. Proukakis, H. T. C Stoof. 2002-02-06. Low-dimensional Bose gases. https://doi.org/10.1103/physreva.66.013615

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