Robust quantum anomalous Hall effect with spatially uncorrelated disorder

TL;DR

This paper demonstrates that the quantum anomalous Hall (QAH) effect remains robust against spatially uncorrelated disorder in magnetic topological insulators, due to quantum confinement effects, offering new insights into its stability with atomic-scale imperfections.

Contribution

The study reveals that the QAH phase is remarkably resilient to uncorrelated disorder, highlighting a novel mechanism involving quantum confinement distinct from quantum percolation.

Findings

QAH phase is robust against spatially uncorrelated disorder

Quantum confinement explains the robustness of QAH effect

Distinct critical behavior from quantum percolation near phase transition

Abstract

In magnetic topological insulators, a phase transition between a quantum anomalous Hall (QAH) and an Anderson localization phase can be triggered by the rotation of an applied magnetic field. Without the scattering paths along magnetic domains, this phase transition is governed by scattering induced by nonmagnetic disorder. We show that the QAH phase is strikingly robust in the presence of spatially uncorrelated disorder. The robustness is attributed to the quantum confinement induced by the short correlation length of the disorder. The critical behavior near the phase transition suggests a picture distinct from quantum percolation. This provides new insights on the robustness of the QAH effect in magnetic topological insulators with atomic defects, impurities, and dopants.