1. State Key Laboratory of Precision Measurement Technology and Instruments, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin 300072, People's Republic of China
2. International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China
3. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200438, People's Republic of China
4. Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China