1. Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
2. Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
3. Department of Physics, Renmin University, Beijing 100872, China
4. School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
5. Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 200240, China
6. Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, China