1. Institute of Atomic and Molecular Physics
2. Sichuan University
3. Chengdu 610065
4. China
5. Department of Physics
6. Florida A&M University
7. Tallahassee
8. USA
9. Nanyang Normal University
10. Nanyang 473061
11. Department of Physics and High Pressure Science and Engineering Center
12. Department of Science and Environmental Studies
13. The Hong Kong Institute of Education
14. Hong Kong