Quantum Anomalous Hall Effect

This simulator models a magnetically doped topological-insulator thin film — the material platform behind the quantum anomalous Hall effect. Ordered magnetic dopants add an exchange field that opens a gap in the film's surface Dirac cones; when the film is thin enough for its top and bottom surfaces to hybridize, that gap becomes topologically nontrivial and a single chiral edge channel forms around the sample boundary, carrying a dissipationless, exactly quantized Hall current with zero applied magnetic field. Toggle the film thickness and magnetization direction, tune the exchange gap and Fermi level, and watch the Chern number, quantized Hall conductance and edge-channel chirality respond in real time — including what happens when the Fermi level leaves the gap and transport degrades to diffusive bulk conduction.