Quantized Anomalous Hall Effect in Magnetic Topological Insulators

TLDR

The anomalous Hall effect, proportional to magnetization and independent of external magnetic field, has been known for over a century but its quantized form has not yet been realized. The study proposes realizing a quantum anomalous Hall system by magnetically doping thin films of three‑dimensional topological insulators and modeling the influence of dopants and film thickness. The authors model magnetically doped topological‑insulator thin films, evaluating how different dopants and film thicknesses affect the quantum anomalous Hall behavior. The calculations predict that the doped films exhibit long‑range ferromagnetic order, making them promising candidates for spintronic applications. Yu et al.

Abstract

Quantum Anomalous Hall Effect In addition to the Hall effect, which appears as a voltage change in conductors in response to an external magnetic field, ferromagnets exhibit the anomalous Hall effect, which is often proportional to their magnetization and independent of the presence of the magnetic field. This effect, first observed more than a century ago, has not been realized in its quantized form. Yu et al. (p. 61 , published online 3 June) propose a realization of a quantum anomalous Hall system by magnetically doping thin films of three-dimensional topological insulators and calculate the effects of various dopants and film thicknesses. The resulting insulators are predicted to have long-range ferromagnetic order, potentially joining dilute magnetic semiconductors as candidates for spintronic applications.