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---MnBi2Te4---by alternate growth of a Bi2Te3 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. The unique magnetic and topological electronic structures and their interplays enable the material to embody rich quantum phases such as quantum anomalous Hall insulators and axion insulators in a well-controlled way.
@article{arxiv.1809.07926,
title = {Experimental realization of an intrinsic magnetic topological insulator},
author = {Yan Gong and Jingwen Guo and Jiaheng Li and Kejing Zhu and Menghan Liao and Xiaozhi Liu and Qinghua Zhang and Lin Gu and Lin Tang and Xiao Feng and Ding Zhang and Wei Li and Canli Song and Lili Wang and Pu Yu and Xi Chen and Yayu Wang and Hong Yao and Wenhui Duan and Yong Xu and Shou-Cheng Zhang and Xucun Ma and Qi-Kun Xue and Ke He},
journal= {arXiv preprint arXiv:1809.07926},
year = {2019}
}