Effects of anisotropy and disorder on the conductivity of Weyl semimetals

TL;DR

This paper investigates how uniaxial anisotropy and impurity scattering influence the dc conductivity of Weyl semimetals, revealing anisotropy-dependent and independent temperature behaviors for different disorder types.

Contribution

It provides a detailed analysis of conductivity anisotropy effects considering various impurity potentials, extending understanding of transport in anisotropic Weyl semimetals.

Findings

Transverse and longitudinal conductivities have different temperature dependencies with short-range disorder.

For long-range disorder, conductivity's temperature dependence (~T^4) is insensitive to anisotropy in certain limits.

The ratio of transverse to longitudinal conductivity depends on anisotropy ratio and temperature.

Abstract

We study dc conductivity of a Weyl semimetal with uniaxial anisotropy (Fermi velocity ratio $\xi= v_\bot/v_\parallel\neq1$) considering the scattering of charge carriers by a wide class of impurity potentials, both short- and long-range. We obtain the ratio of transverse and longitudinal (with respect to the anisotropy axis) conductivities as a function of both $\xi$ and temperature. We find that the transverse and longitudinal conductivities exhibit different temperature dependence in the case of short-range disorder. For general long-range disorder, the temperature dependence ($\sim T^4$) of the conductivity turns out to be insensitive of the anisotropy in the limits of strong ($\xi\gg$ and $\ll1$) and weak ($\xi\approx1$) anisotropy.