Charge transport in gapless chiral electron systems with arbitrary band dispersion

TL;DR

This paper analytically investigates dc charge transport in gapless electron-hole systems with arbitrary band dispersion, revealing how conductivity depends on density and temperature, and distinguishing between semimetallic and metallic behaviors.

Contribution

It provides a general analytical framework for understanding charge transport in gapless systems with arbitrary dispersion and dimensionality, considering both chiral and non-chiral cases.

Findings

Conductivity depends on carrier density and temperature with specific scaling behaviors.

Results distinguish intrinsic semimetallic from extrinsic metallic properties.

Applicable to systems with long-range Coulomb and short-range disorder.

Abstract

Using the semiclassical Boltzmann transport theory, we analytically consider dc charge transport in gapless electron-hole (both chiral and non-chiral) systems in the presence of resistive scattering due to static disorder arising from random quenched impurities in the background. We obtain the dependence of the Boltzmann conductivity on carrier density and temperature for arbitrary band dispersion in arbitrary dimensionality assuming long-range ($\sim 1/r$) Coulomb disorder and zero-range white noise disorder [$\sim \delta(r)$]. We establish that the temperature and the density dependence of the Boltzmann conductivity manifests scaling behaviors determining respectively the intrinsic semimetallic or the extrinsic metallic property of the gapless system. Our results apply equally well to both chiral and non-chiral gapless systems, and provide a qualitative understanding of the dependence of the Boltzmann conductivity on the band dispersion in arbitrary dimensionality.