Thermodynamic measurement of the sound velocity of a Bose gas across the transition to Bose-Einstein condensation

TL;DR

This paper introduces a thermodynamic method to measure sound velocity in Bose gases across the Bose-Einstein condensation transition, providing consistent results and insights into dominant sound modes.

Contribution

It presents a novel thermodynamic approach for measuring sound velocity in Bose gases, applicable across different temperature regimes.

Findings

Sound velocity measurements agree with previous literature.

Method works across quantum and classical regimes.

Insights into thermal and superfluid sound modes.

Abstract

We present an alternative method for determining the sound velocity in atomic Bose-Einstein condensates, based on thermodynamic global variables. The total number of trapped atoms was as a function of temperature carefully studied across the phase transition, at constant volume. It allowed us to evaluate the sound velocity resulting in consistent values from the quantum to classical regime, in good agreement with previous results found in literature. We also provide some insight about the dominant sound mode (thermal or superfluid) across a wide temperature range.