Optical Conductivity of Clean Metals

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 σ is largely dominated by momentum and pseudo-momentum conservation, respectively. In general, the frequency and temperature dependencies of σ(ω,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, Γ ∝ ω, even in the absence of a T 2 contribution.