Robust quantum anomalous Hall effect with spatially uncorrelated disorder

In magnetic topological insulators, a phase transition between quantum anomalous Hall (QAH) and Anderson localization insulating phases 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 a resilience of the topological band gap against disorder, induced by quantum confinement. The critical behavior near the phase transition suggests that the scattering is 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.