1. School of Physical Science and Technology, Southwest University, Chongqing 400715, China
2. Department of Physics, Nanyang Normal University, Nanyang 473061, China
3. Department of Physics and High Pressure Science and Engineering Center, University of Nevada, Las Vegas, Nevada 89154, United States
4. Department of Science and Environmental Studies, The Education University of Hong Kong, Tai Po, NT, Hong Kong, China