Experimental Realization of an Intrinsic Magnetic Topological Insulator
Yan Gong1, Jingwen Guo1, Jiaheng Li1, Kejing Zhu1, Menghan Liao1, Xiaozhi Liu2, Qinghua Zhang2, Lin Gu2, Lin Tang1, Xiao Feng1, Ding Zhang1,3,4, Wei Li1,4, Canli Song1,4, Lili Wang1,4, Pu Yu1,4, Xi Chen1,4, Yayu Wang1,3,4, Hong Yao4,5, Wenhui Duan1,3,4, Yong Xu1,4,6**, Shou-Cheng Zhang7, Xucun Ma1,4, Qi-Kun Xue1,3,4**, Ke He1,3,4**
1State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084 2Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 3Beijing Academy of Quantum Information Sciences, Beijing 100193 4Collaborative Innovation Center of Quantum Matter, Beijing 100084 5Institute for Advanced Study, Tsinghua University, Beijing 100084 6RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan 7Stanford Center for Topological Quantum Physics, Department of Physics, Stanford University, Stanford, California 94305-4045, USA
Abstract：An 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 remained elusive experimentally for a long time. Here we report the experimental realization of 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. 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 at higher temperature and in a well-controlled way.
2019, Vol. 36 
