Only Fermi-Liquids are Metals

TL;DR

This paper discusses how deviations from Landau Fermi-liquid theory in metals lead to a vanishing density of states and infinite resistivity at zero temperature, with applications to copper-oxide superconductors.

Contribution

It introduces a framework linking non-Fermi-liquid behavior to impurity effects and density of states suppression at zero temperature.

Findings

Deviations cause density of states to vanish at the chemical potential.

Impurities lead to infinite resistivity as temperature approaches zero.

Application to copper-oxide metals explains resistivity anisotropy.

Abstract

Any singular deviation from Landau Fermi-liquid theory appears to lead, for arbitrarily small concentration of impurities coupling to a non-conserved quantity, to a vanishing density of states at the chemical potential and infinite resistivity as temperature approaches zero. Applications to copper-oxide metals including the temperature dependence of the anisotropy in resistivity, and to other cases of non Fermi-liquids are discussed.