Nonlinear planar magnetotransport due to tilted Dirac cones in topological materials

TL;DR

This paper explains the nonlinear planar magnetotransport observed in topological materials as resulting from tilted Dirac cones and charge puddles, supported by a network model matching experimental data.

Contribution

It introduces a network model that captures the effects of tilted Dirac cones and charge puddles on nonlinear magnetotransport in topological materials.

Findings

Tilted Dirac cones cause nonlinear magnetotransport.

Charge puddles influence transport behavior.

Model aligns with experimental observations.

Abstract

Nonlinear planar magnetotransport is ubiquitous in topological HgTe structures, both in tensile (topological insulator) or compressively strained layers (Weyl semimetal phase). We show that the common reason for the nonlinear planar magnetotransport is the presence of tilted Dirac cones combined with the formation of charge puddles. The origin of the tilted Dirac cones is the mix of the Zeeman term due to the in-plane magnetic field and quadratic contributions to the dispersion relation. We develop a network model that mimics transport of tilted Dirac fermions in the landscape of charge puddles. The model captures the essential features of the experimental data. It should be relevant for nonlinear planar magnetotransport in a variety of topological and small band gap materials.