1. Department of Physics
2. South University of Science and Technology of China
3. 518055 Shenzhen
4. China
5. Institute for Structure and Function & Department of Physics
6. Dalian Institute of Chemical Physics
7. Department of Applied Physics
8. Nanjing University of Science and Technology
9. Nanjing
10. P. R. China
11. Key Laboratory of Advanced Technology of Materials (Ministry of Education)
12. School of Science and Engineering