Experimental realization of an intrinsic magnetic topological insulator

Understand

Intrinsic magnetic topological insulator (TI) is a stoichiometric magnetic compound possessing both inherent magnetic order and topological electronic states.

• Such a material can provide a shortcut to various novel topological quantum effects but remains elusive experimentally so far.
• Here, we report the experimental realization of high-quality thin films of an intrinsic magnetic TI---MnBi$_2$Te$_4$---by alternate growth of a Bi$_2$Te$_3$ quintuple-layer and a MnTe bilayer with molecular beam epitaxy.
• The material shows the archetypical Dirac surface states in angle-resolved photoemission spectroscopy and is demonstrated to be an antiferromagnetic topological insulator with ferromagnetic surfaces by magnetic and transport measurements as well as first-principles calculations.