Anisotropic transverse magnetoresistance temperature dependence in Mn3Ga Weyl semimetal with chiral anomaly

TL;DR

This study investigates the anisotropic transverse magnetoresistance in Mn3Ga Weyl semimetals, revealing temperature-dependent transitions and spin structure reordering, with implications for topological transport properties.

Contribution

It provides the first detailed analysis of transverse magnetoresistance in Mn3Ga, linking experimental observations with first principles calculations of spin structure changes.

Findings

Transition from negative linear to positive quadratic magnetoresistance between 200-300 K

Metallic to semiconductor transition at 230 K

Asymmetry in magnetoresistance due to self-spin polarized currents

Abstract

Hexagonal antiferromagnetic D019-Mn3X (X = Sn, Ge, Ga) compounds, with a non-collinear Kagome spin structure, are Weyl semimetals exhibiting novel topological transport properties. The longitudinal magnetoresistance of c-oriented epitaxial Ru/Mn3Ga thin films exhibits a positive quadratic dependence on magnetic field over a wide range of temperatures. Here we describe the transverse magnetoresistance, with the field in the out-of-plane direction, for c-oriented epitaxial GaN (0001)/Mn3Ga films. There is a transition from a negative linear to a positive quadratic dependence on magnetic field in the temperature range from 200 K to 300 K. The electrical resistivity shows a metallic to semiconductor transition at 230 K. By applying the electric field along two perpendicular in-plane directions we find asymmetry in the magnetoresistance curves due to self-spin polarized currents created through magnetic octupole clusters. First principles calculations confirmed the metallic to semiconductor transition corresponds to reordering the spin structure to a higher symmetry configuration.