Landau Damping in a Mixture of Bose and Fermi Superfluids

TL;DR

This paper investigates how Landau damping behaves in a mixture of Bose and Fermi superfluids at finite temperature, revealing exponential suppression at low temperatures and differing momentum dependencies across the BCS and BEC regimes.

Contribution

It provides a detailed analysis of Landau damping rates in Bose-Fermi superfluid mixtures, highlighting their temperature dependence and momentum characteristics across different superfluid regimes.

Findings

Landau damping rate is exponentially suppressed at low temperatures.

Damping rate's momentum dependence differs between BCS and BEC sides.

Results relate to collective mode experiments in Bose-Fermi mixtures.

Abstract

We study the Landau damping in Bose-Fermi superfluid mixture at finite temperature. We find that at low temperature, the Landau damping rate will be exponentially suppressed at both the BCS side and the BEC side of Fermi superfluid. The momentum dependence of the damping rate is obtained, and it is quite different from the BCS side to the BEC side. The relations between our result and collective mode experiment in the recently realized Bose-Fermi superfluid mixture are also discussed.