Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi$_2$Te$_4$

Understand

In a magnetic topological insulator, nontrivial band topology conspires with magnetic order to produce exotic states of matter that are best exemplified by quantum anomalous Hall (QAH) insulators and axion insulators.

• Up till now, such magnetic topological insulators are obtained by doping topological insulators with magnetic atoms.
• The random magnetic dopants, however, inevitably introduce disorders that hinder further exploration of quantum effects in the material.
• Here, we resolve this dilemma by probing quantum transport in MnBi$_2$Te$_4$ thin flake - a topological insulator with intrinsic magnetic order.