1. International Laboratory for Quantum Functional Materials of Henan, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
2. School of Materials Science and Engineering, Beihang University, Beijing 100191, China
3. Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
4. Institute for Advanced Study, Tsinghua University, Beijing 100084, China