Quantum Anomalous Hall Effect and Anderson Chern Insulating Regime in Noncollinear Antiferromagnetic 3Q State

TL;DR

This paper explores how noncollinear antiferromagnetic 3Q states in 2D hexagonal lattices can host quantum anomalous Hall and Anderson Chern insulating phases without spin-orbit coupling, revealing potential for spintronics.

Contribution

It demonstrates the emergence of topological phases and edge states in antiferromagnetic 3Q states using tight-binding models, highlighting their robustness and disorder-induced transitions.

Findings

Observation of spin-polarized edge currents with energy-dependent chirality.

Disorder-induced transition from trivial metal to topological insulator.

Robustness of edge channels against deformation and disorder.

Abstract

We investigate the emergence of both quantum anomalous Hall and disorder-induced Anderson Chern insulating phases in two dimensional hexagonal lattices, with antiferromagnetically ordered 3Q state and in the absence of spin-orbit coupling. Using tight-binding modeling, we show that such systems display not only a spin-polarized edge-localized current, the chirality of which is energy dependent but also an impurity-induced transition from trivial metallic to topological insulating regimes, through one edge mode plateau. We compute the gaps' phase diagrams, and demonstrate the robustness of the edge channel against deformation and disorder. Our study hints at the 3Q state as a promising building block for dissipationless spintronics based on antiferromagnets.