Hydrodynamic excitations of trapped dipolar fermions

TL;DR

This paper studies the collective excitations of trapped dipolar fermions to identify signs of mechanical collapse caused by attractive dipole interactions, using variational and numerical hydrodynamic methods.

Contribution

It introduces a combined variational and numerical approach to analyze the instability signatures in the collective excitation spectrum of dipolar fermions.

Findings

Identification of instability signatures in excitation spectrum

Comparison of variational and numerical hydrodynamic results

Insights into collapse mechanisms of dipolar Fermi gases

Abstract

A single-component Fermi gas of polarized dipolar particles in a harmonic trap can undergo a mechanical collapse due to the attractive part of the dipole-dipole interaction. This phenomenon can be conveniently manipulated by the shape of the external trapping potential. We investigate the signatures of the instability by studying the spectrum of low-lying collective excitations of the system in the hydrodynamic regime. To this end, we employ a time-dependent variational method as well as exact numerical solutions of the hydrodynamic equations of the system.