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arXiv · 0807.2418

Damped bounces of an isolated perfect quantum gas

S. Camalet
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Abstract

The issue of the thermalization of an isolated quantum system is addressed by considering a perfect gas confined by gravity and initially trapped above a certain height. As we are interested in the behavior of truly isolated systems, we assume the gas is in a pure state of macroscopically well-defined energy. We show that, in general, for single-particle distributions, such a state is strictly equivalent to the microcanonical mixed state at the same energy. We derive an expression for the time-dependent gas density which depends on the initial gas state only via a few thermodynamic parameters. Though we consider non-interacting particles, the density relaxes into an asymptotic profile, but which is not the thermal equilibrium one determined by the gas energy and particle number.

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S. Camalet. 2008-09-22. Damped bounces of an isolated perfect quantum gas. https://doi.org/10.1103/physreve.78.061112

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