Temperature and finite-size effects in collective modes of superfluid Fermi gases

TL;DR

This paper investigates how superfluidity influences collective excitations in ultra-cold Fermi gases, analyzing temperature and trap effects using microscopic methods and comparing with hydrodynamic models.

Contribution

It provides a detailed microscopic analysis of temperature and finite-size effects on collective modes in superfluid Fermi gases, highlighting the limits of semiclassical approaches.

Findings

Superfluidity significantly alters monopole and quadrupole modes.

Temperature and trap frequency impact collective excitation spectra.

Hydrodynamic predictions are valid within specific regimes.

Abstract

We study the effects of superfluidity on the monopole and quadrupole collective excitations of a dilute ultra-cold Fermi gas with an attractive interatomic interaction. The system is treated fully microscopically within the Bogoliubov-de Gennes and quasiparticle random-phase approximation methods. The dependence on the temperature and on the trap frequency is analyzed and systematic comparisons with the corresponding hydrodynamic predictions are presented in order to study the limits of validity of the semiclassical approach.