1. Key Laboratory of Artificial Micro‐ and Nano‐structures of Ministry of Education and School of Physics and Technology Wuhan University Wuhan 430072 P. R. China
2. School of Materials Science and Engineering Peking University Beijing 100871 P. R. China
3. Wuhan Institute of Quantum Technology Wuhan 430206 P. R. China
4. International College University of Chinese Academy of Sciences Beijing 100190 P. R. China
5. Hubei Luojia Laboratory Wuhan 430072 P. R. China