1. Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology
2. Wuhan University
3. Wuhan 430072
4. China
5. The Institute of Technological Sciences
6. School of Science
7. Wuhan Institute of Technology
8. Wuhan 430205
9. School of Physics and Materials Science
10. Henan Normal University
11. Xinxiang 453007