1. School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
2. Department of Physics, Wuhan University of Technology, Wuhan 430074, China
3. School of Physics Science and Technology, Anshan Normal University, Anshan 114007, China
4. Shanghai Bright-Tech Information Technology Co. Ltd, Shanghai 201206, China
5. Research Group PLASMANT, Department of Chemistry, University of Antwerp, B-2610 Wilrijk-Antwerp, Belgium