Magnetoresistance due to Broken C4 Symmetry in Cubic B20 Chiral Magnets

TL;DR

This paper investigates the unusual magnetoresistance in B20 chiral magnets, revealing the effects of broken C4 symmetry through experimental observations and a minimal microscopic theory.

Contribution

It introduces a minimal two-spin-orbit-term theory that explains magnetoresistance due to broken C4 symmetry in B20 chiral magnets.

Findings

Magnetoresistance directly indicates broken C4 symmetry.

The microscopic theory accounts for transport experimental results.

The study links symmetry breaking to observable electronic properties.

Abstract

The B20 chiral magnets with broken inversion symmetry and C4 rotation symmetry have attracted much attention. The broken inversion symmetry leads to the Dzyaloshinskii-Moriya that gives rise to the helical and Skyrmion states. We report the unusual magnetoresistance (MR) of B20 chiral magnet Fe0.85Co0.15Si that directly reveals the broken C4 rotation symmetry. We present a microscopic theory, a minimal theory with two spin-orbit terms, that satisfies all the symmetry requirements and accounts for the transport experiments.