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First and second sound in a uniform Bose gas

A. Griffin·E. Zaremba
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Abstract

We have recently derived two-fluid hydrodynamic equations for a trapped weakly-interacting Bose gas. In this paper, we use these equations to discuss first and second sound in a uniform Bose gas. These results are shown to agree with the predictions of the usual two-fluid equations of Landau when the thermodynamic functions are evaluated for a weakly-interacting gas. In a uniform gas, second sound mainly corresponds to an oscillation of the superfluid (the condensate) and is the low frequency continuation of the Goldstone-Bogoliubov symmetry-breaking mode.

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A. Griffin, E. Zaremba. 1997-07-05. First and second sound in a uniform Bose gas. https://doi.org/10.1103/physreva.56.4839

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