Density wave instability in a 2D dipolar Fermi gas

TL;DR

This paper investigates the stability and density wave instabilities in a 2D dipolar Fermi gas, revealing conditions for density wave formation and potential high critical temperatures in realistic molecular systems.

Contribution

It provides a theoretical analysis of density wave instability in 2D dipolar Fermi gases using Hartree-Fock and RPA, highlighting conditions for stability and high critical temperatures.

Findings

Density wave instability occurs in a broad stable region.

Critical temperature can be a significant fraction of Fermi temperature.

System remains stable against collapse while exhibiting density waves.

Abstract

We consider a uniform dipolar Fermi gas in two-dimensions (2D) where the dipole moments of fermions are aligned by an orientable external field. We obtain the ground state of the gas in Hartree-Fock approximation and investigate RPA stability against density fluctuations of finite momentum. It is shown that the density wave instability takes place in a broad region where the system is stable against collapse. We also find that the critical temperature can be a significant fraction of Fermi temperature for a realistic system of polar molecules.