A theoretical study on the damping of collective excitations in a Bose-Einstein condensate

TL;DR

This paper provides a theoretical analysis of how collective excitations in a Bose-Einstein condensate are damped, deriving a general expression for the damping rate applicable across temperature regimes and comparing predictions with experiments.

Contribution

It introduces a new theoretical expression for damping rates of collective excitations in Bose-Einstein condensates across different temperature regimes.

Findings

Derived a general damping rate expression for low-lying excitations

Predicted damping rates consistent with experimental data at higher temperatures

Extended theoretical understanding of condensate dynamics in weakly interacting gases

Abstract

We study the damping of low-lying collective excitations of condensates in a weakly interacting Bose gas model within the framework of imaginary time path integral. A general expression of the damping rate has been obtained in the low momentum limit for both the very low temperature regime and the higher temperature regime. For the latter, the result is new and applicable to recent experiments. Theoretical predictions for the damping rate are compared with the experimental values.