1. National Laboratory of Solid State Microstructures
2. Collaborative Innovation Center of Advanced Microstructures
3. School of Physics
4. Nanjing University
5. Nanjing 210093
6. College of Chemistry and Chemical Engineering
7. Yangzhou University
8. Yangzhou
9. China
10. Faculty of Informatics and Engineering
11. the University of Electro-Communications
12. Tokyo 182-8585
13. Japan