1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Nano-Optoelectronics Frontier Center of Ministry of Education (NFC-MOE), Peking University, Beijing 100871, China
2. Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
3. Collaborative Innovation Center of Quantum Matter, Beijing 100871, China