1. Shanghai Key Laboratory of High Temperature Superconductors, Physics Department, Shanghai University, Shanghai 200444, China
2. International Center for Quantum and Molecular Structures, Shanghai University, Shanghai 200444, China
3. 2-Dimensional Crystal Consortium, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
4. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
5. Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan
6. Research Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0044, Japan