Non-Fermi liquid behavior in nearly charge ordered layered metals

TL;DR

This paper demonstrates that nearly charge-ordered two-dimensional metals exhibit non-Fermi liquid behavior characterized by linear temperature-dependent scattering rates and increased effective mass, aligning with experimental observations in organic conductors.

Contribution

It provides a theoretical explanation for non-Fermi liquid behavior near charge ordering transitions in layered metals, supported by comparison with experimental optical conductivity data.

Findings

Linear T dependence of scattering rate above T*

Increase in electron effective mass above T*

Qualitative agreement with optical conductivity measurements

Abstract

Non-Fermi liquid behavior is shown to occur in two-dimensional metals which are close to a charge ordering transition driven by the Coulomb repulsion. A linear temperature dependence of the scattering rate together with an increase of the electron effective mass occur above T*, a temperature scale much smaller than the Fermi temperature. It is shown that the anomalous temperature dependence of the optical conductivity of the quasi-two-dimensional organic metal alpha-(BEDT-TTF)2MHg(SCN)4, with M=NH4 and Rb, above T*=50-100 K, agrees qualitatively with our predictions for the electronic properties of nearly charge ordered two-dimensional metals.