Planar Hall effect in antiferromagnetic MnTe thin films

TL;DR

This paper investigates the planar Hall effect in antiferromagnetic MnTe thin films, revealing how spin-orbit coupling influences transport properties and quantifying the effect's maximum magnitude through theoretical models and first-principles calculations.

Contribution

The study introduces a minimal theoretical model capturing the spin-orbit induced band splitting and quantitatively estimates the maximum planar Hall effect in MnTe.

Findings

Spin-orbit coupling causes anisotropic valence-band splitting in MnTe.

The zero-field planar Hall effect symmetry is explained by the model.

Maximum PHE percentage is estimated to be approximately 31%.

Abstract

We show that the spin-orbit coupling (SOC) in alpha-MnTe impacts the transport behavior by generating an anisotropic valence-band splitting, resulting in four spin-polarized pockets near Gamma. A minimal k-dot-p model is constructed to capture this splitting by group theory analysis, a tight-binding model and ab initio calculations. The model is shown to describe the rotation symmetry of the zero-field planer Hall effect (PHE). The upper limit of the PHE percentage is shown to be fundamentally determined by the band shape, and is quantitatively estimated to be roughly 31% by first principles.