Topological phase transitions induced by correlated magnetic disorder in two-dimensional quantum anomalous Hall system

A topological Anderson insulator is an intriguing transport phenomenon typically driven by short-range nonmagnetic disorder, and the interplay between disorder and magnetism plays a crucial role in the topological phase diagram of two-dimensional electron systems. Here, by performing nonequilibrium Green's function transport calculations, we numerically demonstrate that long-range correlated magnetic disorder can induce topological phase transitions in a two-dimensional quantum anomalous Hall system. We show that spatially correlated magnetic fluctuations can drive a trivial insulator into a topologically nontrivial phase, characterized by quantized conductance arising from chiral edge currents. We further reveal the crucial role of the disorder correlation length and system size in stabilizing this topological phase. Additionally, by comparing the transport properties of systems with correlated and short-range magnetic disorder, we identify the distinctive characteristics of topological phase transitions induced by correlated magnetic disorder. Our findings uncover a new route toward disorder-engineered topological phases via correlated magnetic disorder, and they provide guidance for realizing robust topological transport in disordered magnetic systems.