1. International Center for Quantum Materials, School of Physics, Peking University 1 , Beijing 100871, China
2. Collaborative Innovation Center of Quantum Matter 2 , Beijing 100871, China
3. Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University 3 , Beijing 100871, China
4. Department of Electrical and Computer Engineering, Department of Physics and Astronomy, and Department of Materials Science and Engineering, University of California 4 , Los Angeles, California 90095, USA
5. School of Science and Engineering, The Chinese University of Hong Kong 5 , Shenzhen, Guangdong 518172, China
6. University of Science and Technology of China 6 Department of Chemical Physics, , Hefei, Anhui 230026, China
7. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences 7 Beijing 100190, China