paper

Exact perturbative expansion of the transport coefficients of a normal low-temperature Fermi gas with contact interactions

arXiv:2502.03423 · doi:10.1103/c6fd-x57s

Abstract

We compute the shear viscosity, thermal conductivity and spin diffusivity of a Fermi gas with short-range interactions in the Fermi liquid regime of the normal phase, that is at temperatures much lower than the Fermi temperature and much larger than the superfluid critical temperature . Given recent advances in the precision of cold atom experiments, we provide exact results up to second-order in the interaction strength. We extend the Landau-Salpeter equation to compute the collision amplitude beyond the forward-scattering limit, covering all collisions on the Fermi surface. We treat the collision kernel exactly, leading to significant corrections beyond relaxation-time or variational approximations. The transport coefficients, as functions of the -wave scattering length and Fermi wavenumber , follow up to corrections of order , with a positive coefficient for the viscosity and negative one for the thermal conductivity and spin diffusivity.

10 pages, 1 figure, 2 tables

References in corpus (19)