Berry curvature induced magnetotransport in 3D noncentrosymmetric metals

TL;DR

This paper investigates how Berry curvature influences magnetotransport in 3D noncentrosymmetric metals, revealing quadratic magnetic field dependencies and phenomena like negative magnetoresistance and planar Hall effects, with results depending on Fermi energy relative to band touching points.

Contribution

It introduces a semiclassical Boltzmann approach incorporating Berry curvature and orbital magnetic moment to analyze magnetotransport in noncentrosymmetric metals, highlighting new effects and dependencies.

Findings

Quadratic-B dependence of conductivities due to Berry curvature effects

Observation of negative magnetoresistance and planar Hall effect

Dependence of magnetoresistance on Fermi energy and Rashba coupling

Abstract

We study the magnetoelectric and magnetothermal transport properties of noncentrosymmetric metals using semiclassical Boltzmann transport formalism by incorporating the effects of Berry curvature and orbital magnetic moment. These effects impart quadratic-B dependence to the magnetoelectric and magnetothermal conductivities, leading to intriguing phenomena such as planar Hall effect, negative magnetoresistance, planar Nernst effect and negative Seebeck effect. The transport coefficients associated with these effects show the usual oscillatory behavior with respect to the angle between the applied electric field and magnetic field. The bands of noncentrosymmetric metals are split by Rashba spin-orbit coupling except at a band touching point. For Fermi energy below (above) the band touching point, giant (diminished) negative magnetoresistance is observed. This difference in the nature of magnetoresistance is related to the magnitudes of the velocities, Berry curvature and orbital magnetic moment on the respective Fermi surfaces, where the orbital magnetic moment plays the dominant role. The absolute magnetoresistance and planar Hall conductivity show a decreasing (increasing) trend with Rashba coupling parameter for Fermi energy below (above) the band touching point.