1. School of Physical Science and Technology, Southwest University, Chongqing 400715, China
2. Department of Physics, Nanyang Normal University, Nanyang 473061, China
3. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
4. Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, New
Territories, Hong Kong, China
5. School of Science, Northwestern Polytechnic University, Xi’an 710072, China