1. Department of Applied Physics
2. School of Science
3. Nanjing University of Science and Technology
4. 210094 Nanjing
5. China
6. Key Laboratory for Microstructural Material Physics of Hebei Province
7. Yanshan University
8. Qinhuangdao 066004
9. Hefei National Laboratory for Physical Science at the Microscale
10. University of Science and Technology of China
11. 230026 Hefei