Magnetotransport in multi-Weyl semimetals: A kinetic theory approach

TL;DR

This paper investigates the magnetotransport properties of multi-Weyl semimetals, revealing how the longitudinal magnetoconductivity scales with magnetic field and monopole charge, and analyzing the effects of different scattering mechanisms.

Contribution

It provides a kinetic theory analysis of magnetotransport in multi-Weyl semimetals, highlighting the $n^3$ scaling of LMC and the impact of scattering times on chiral anomaly signatures.

Findings

LMC scales as $B^2$ and $n^3$ with monopole charge.

LMC is insensitive to magnetic field direction for $n>1$.

Chiral anomaly contribution dominates at large inter-valley scattering times.

Abstract

We study the longitudinal magnetotransport in three-dimensional multi-Weyl semimetals, constituted by a pair of (anti)-monopole of arbitrary integer charge ($n$), with $n=1,2$ and $3$ in a crystalline environment. For any $n>1$, even though the distribution of the underlying Berry curvature is anisotropic, the corresponding intrinsic component of the longitudinal magnetoconductivity (LMC), bearing the signature of the chiral anomaly, is insensitive to the direction of the external magnetic field ($B$) and increases as $B^2$, at least when it is sufficiently weak (the semi-classical regime). In addition, the LMC scales as $n^3$ with the monopole charge. We demonstrate these outcomes for two distinct scenarios, namely when inter-particle collisions in the Weyl medium are effectively described by (a) a single and (b) two (corresponding to inter- and intra-valley) scattering times. While in the former situation the contribution to LMC from chiral anomaly is inseparable from the non-anomalous ones, these two contributions are characterized by different time scales in the later construction. Specifically for sufficiently large inter-valley scattering time the LMC is dominated by the anomalous contribution, arising from the chiral anomaly. The predicted scaling of LMC and the signature of chiral anomaly can be observed in recently proposed candidate materials, accommodating multi-Weyl semimetals in various solid state compounds.