1. School of Physics and Information Technology, Shaanxi Normal University, Xi’an 710119, China
2. Institute of Functional Nano and Soft Materials (FUNSOM) & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123, China
3. School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, United Kingdom
4. School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China