1. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
2. University of Chinese Academy of Sciences, Beijing 100049, China
3. National Laboratory of Solid-State Microstructures, School of Physics and Collaborative Innovation Centre of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
4. Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
5. ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China
6. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
7. Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
8. State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
9. School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China
10. Department of Physics, University of Oxford, Oxford, OX1 3PU, U.K.