# Thermal conductivity of the degenerate one-dimensional Fermi gas

## TL;DR

This paper develops a microscopic theory for heat transport in a one-dimensional degenerate Fermi gas, revealing two distinct relaxation processes affecting thermal conductivity at low temperatures.

## Contribution

It introduces the concept of thermal conductivity of elementary excitations and analyzes their role in heat dissipation in weakly interacting 1D Fermi gases.

## Key findings

- Identification of two relaxation processes with different rates
- Introduction of thermal conductivity of elementary excitations
- Quantitative description of heat transport at low temperatures

## Abstract

We study heat transport in a gas of one-dimensional fermions in the presence of a small temperature gradient. At temperatures well below the Fermi energy there are two types of relaxation processes in this system, with dramatically different relaxation rates. As a result, in addition to the usual thermal conductivity, one can introduce the thermal conductivity of the gas of elementary excitations, which quantifies the dissipation in the system in the broad range of frequencies between the two relaxation rates. We develop a microscopic theory of these transport coefficients in the limit of weak interactions between the fermions.