1. Department of Physics and Hefei National Laboratory for Physical Science at Microscale University of Science and Technology of China Hefei Anhui 230026 P. R. China
2. College of Physics and Institute of Advanced Interdisciplinary Studies Chongqing University Chongqing 401331 P. R. China
3. College of Materials Science and Engineering Chongqing University Chongqing 401331 P. R. China
4. Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 P. R. China