Shear viscosity and damping of collective modes in a two-dimensional Fermi gas

TL;DR

This paper calculates the shear viscosity of a 2D Fermi gas using kinetic theory, showing it is comparable to 3D gases, and applies results to experimental damping data.

Contribution

It provides the first kinetic theory calculation of shear viscosity in a 2D Fermi gas and compares it with experimental observations.

Findings

Shear viscosity to entropy density ratio is similar to 3D unitary gases.

Damping of collective modes matches experimental data.

Kinetic theory effectively describes strongly interacting 2D Fermi gases.

Abstract

We compute the shear viscosity of a two dimensional Fermi gas interacting via a short range potential with scattering length $a_{2d}$ in kinetic theory. We find that kinetic theory predicts that the shear viscosity to entropy density ratio of a strongly interacting two dimensional gas is comparable to that of the three dimensional unitary gas. We use our results to compute the damping of collective modes in a trapped Fermi gas, and compare to experimental data recently obtained in E. Vogt et al., arXiv:1111.1173.