1. Department of Physics, Shaanxi University of Science and Technology, Xi’an, 710021, P. R. China
2. School of Science, Xi’an University of Posts and Telecommunications, Xi’an, 710121, P. R. China
3. Institute of Atomic and Molecular Physics, Key Laboratory of High Energy Density Physics and Technology, Ministry of Education, Sichuan University, Chengdu, P. R. China
4. School of Electronic Engineering, Chengdu Technological University, Chengdu, P. R. China