1. Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
2. State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China
3. Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics, Hunan University, Changsha 410082, China
4. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
5. Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
6. Department of Physics, South University of Science and Technology of China, Shenzhen 518055, China