1. International Center for Quantum Materials, Peking University, Beijing 100871, China.
2. Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China.
3. School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China.
4. State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
5. State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China.
6. Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
7. Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China.