1. School of Science, China University of Geosciences (Beijing) 1 , Beijing 100083, China
2. Zhengzhou Institute, China University of Geosciences (Beijing) 2 , Zhengzhou 451283, China
3. Institute of Physics, Chinese Academy of Sciences 3 , Beijing 100083, China
4. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences 4 , Beijing 100190, China