Optical Conductivity of Clean Metals

TL;DR

This paper reviews the fundamental aspects of electrical transport in clean metals, emphasizing the effects of electron-electron interactions and how they influence conductivity without impurities or phonons.

Contribution

It provides a theoretical analysis of how electron-electron interactions affect conductivity in various Fermi surface geometries, highlighting differences in frequency and temperature dependencies.

Findings

Conductivity is dominated by momentum conservation in small Fermi surfaces.

Frequency dependence of scattering rate is quadratic, Gamma ∝ w^2, even without T^2 contributions.

Different Fermi surface geometries lead to distinct transport behaviors.

Abstract

We briefly review some basic aspects of transport in clean metals focusing on the role of electron-electron interactions and neglecting the effects of impurities, phonons and interband transitions. Both for small Fermi surfaces of two and three-dimensional metals and open Fermi surfaces of quasi one-dimensional metals the dc conductivity sigma is largely dominated by momentum and pseudo-momentum conservation, respectively. In general, the frequency and temperature dependencies of sigma(w,T) have very little in common. For small Fermi surfaces in three dimensions we find for example that the scattering rate is quadratic in frequency, Gamma \propto w^2, even in the absence of a T^2 contribution.