Switchable anomalous Hall effect by selective mirror symmetry breaking in a kagome magnet GdMn6Ge6

TL;DR

This study demonstrates how external magnetic fields can selectively break mirror symmetries in GdMn6Ge6, enabling controllable switching of its topological electronic states and anomalous Hall effect.

Contribution

It provides the first experimental and theoretical evidence of symmetry-controlled topological state switching in a kagome magnet.

Findings

Magnetic field induces mirror symmetry breaking.

Switchable anomalous Hall effect observed.

First-principles calculations support experimental results.

Abstract

The crystal symmetry plays a pivotal role in protecting the nontrivial electronic states in a topological phase. Manipulation of the crystal symmetry and hence the nontrivial topological states would serve as a fertile ground to explore exotic topological properties. Combining experimental and theoretical investigations, we demonstrate herein the flexible switch of nontrivial topological states in the single phase of kagome magnet GdMn6Ge6. The intrinsic anomalous Hall effect caused by distinct Berry curvatures along different crystallographic directions is realized through selectively breaking the mirror symmetries in these directions by external magnetic field, which is fully supported by the first-principles calculations. Our results set an explicit example demonstrating the strong correlation between structure symmetry and nontrivial topological states, as well as the switchable topological properties in a single magnetic topological phase.