1. School of Physics and Optoelectronic Engineering
2. Nanjing University of Information Science & Technology
3. Nanjing 210044
4. China
5. Department of Physics
6. Herbert Gleiter Institute of Nanoscience
7. College of Materials Science and Engineering
8. Nanjing University of Science and Technology
9. Nanjing 210094
10. Department of Chemistry
11. National University of Singapore
12. Singapore
13. School of Physics and Electronics
14. Central South University
15. Changsha 100083
16. Institute for Advanced Study and Department of Physics
17. Nanchang University
18. Nanchang 330000
19. Singapore 117542