Marginal Fermi Liquid from a Partially Nested Fermi Surface and Impurity Scattering in a Two Dimensional Metal

TL;DR

This paper demonstrates that in a two-dimensional metal with a partially nested Fermi surface, impurity scattering induces a linear energy dependence in quasiparticle decay rates, resembling Marginal Fermi Liquid behavior, relevant to unconventional superconductors.

Contribution

It shows that even small nested Fermi surface sections can produce Marginal Fermi Liquid-like decay rates due to impurity scattering in 2D metals.

Findings

Linear energy dependence of quasiparticle decay rates across the Fermi surface.

Largest linear coefficient along nested regions, finite elsewhere.

Dependence of decay rates on impurity scattering rate elta.

Abstract

The electron-electron scattering rate of low-energy quasiparticles is computed perturbatively for a two-dimensional metal with a partially nested Fermi surface, a weak electron-electron interaction and an energy-independent impurity scattering rate. We show that even when the nested section comprises only a small fraction of the Fermi surface, the low energy quasiparticle decay rates throughout the Fermi surface gain a term which is linear in energy $\omega$. The coefficient of this linear contribution is largest along the nested regions but remains finite elsewhere, and is strongly dependent on the impurity scattering rate $\delta$. We discuss the possible relevance of this result to unconventional superconductors (such as the cuprates) and to the normal state of charge density wave materials such as the rare Earth tellurides.