Compressibility, zero sound, and effective mass of a fermionic dipolar gas at finite temperature

TL;DR

This paper investigates the finite-temperature properties of a fermionic dipolar gas, revealing nonmonotonic compressibility and temperature-dependent collective modes, with implications for experimental detection of quantum degeneracy effects.

Contribution

It provides a comprehensive calculation of compressibility, zero sound, and effective mass across various dimensions at finite temperature, highlighting new nontrivial behaviors.

Findings

Compressibility exhibits a maximum at finite temperature.

Zero sound mode can propagate at experimentally accessible temperatures.

Effective mass shows nontrivial temperature and density dependence.

Abstract

The compressibility, zero sound dispersion, and effective mass of a gas of fermionic dipolar molecules is calculated at finite temperature for one-, two-, and three-dimensional uniform systems, and in a multilayer quasi-two-dimensional system. The compressibility is nonmonotonic in the reduced temperature, $T/T_F$, exhibiting a maximum at finite temperature. This effect might be visible in a quasi-low-dimensional experiment, providing a clear signature of the onset of many-body quantum degeneracy effects. The collective mode dispersion and effective mass show similar nontrivial temperature and density dependence. In a quasi-low-dimensional system, the zero sound mode may propagate at experimentally attainable temperatures.