1. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
2. Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100190, China
3. National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
4. Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
5. ShanghaiTech Laboratory for Topological Physics, Shanghai 201210, China