1. Physics Department
2. Virginia Commonwealth University
3. Richmond
4. USA
5. Department of Applied Physics and Institution of Energy and Microstructure
6. College of Information Science and Technology
7. Nanjing Forestry University
8. Nanjing
9. P. R. China
10. National Laboratory of Solid State Microstructures and School of Physics
11. Nanjing University
12. Nanjing 210093
13. Nanjing University of Science and Technology