Longitudinal magnetoconductance and the planar Hall conductance in inhomogeneous Weyl semimetals

TL;DR

This paper investigates how strain and magnetic fields influence magnetoconductance and planar Hall conductance in inhomogeneous Weyl semimetals, revealing sign-reversal phenomena and complex phase diagrams due to chiral gauge fields.

Contribution

It introduces a comprehensive analysis of strain-induced chiral gauge fields and their impact on magnetotransport, including sign-reversal effects and the interplay with external magnetic fields in Weyl semimetals.

Findings

Strain-induced chiral gauge fields cause strong sign-reversal of LMC.

External magnetic fields induce sign-reversal only with strong intervalley scattering.

The combined effects produce complex features in the LMC phase diagram.

Abstract

Elastic deformations (strain) couple to the electronic degrees of freedom in Weyl semimetals as an axial magnetic field (chiral gauge field), which in turn affects their impurity dominated diffusive transport. Here we study the longitudinal magnetoconductance (LMC) in the presence of strain, Weyl cone tilt, and finite intervalley scattering, taking into account the momentum dependence of the scattering processes (both internode and intranode), as well as charge conservation. We show that strain induced chiral gauge field results in `strong sign-reversal' of the LMC, which is characterized by the reversal of orientation of the magnetoconductance parabola with respect to the magnetic field. On the other hand, external magnetic field results in `strong sign-reversal', only for sufficiently strong intervalley scattering. When both external and chiral gauge fields are present, we observe both strong and weak sign-reversal, where in the case of weak sign-reversal, the rise and fall of magnetoconductivity depends on the direction of the magnetic field and/or the chiral gauge field, and is not correlated with the orientation of the LMC parabola. The combination of the two fields is shown to generate striking features in the LMC phase diagram as a function of various parameters such as tilt, strain, and intervalley scattering. We also study the effect of strain induced chiral gauge field on the planar Hall conductance and highlight its distinct features that can be probed experimentally.