1. State Key Laboratory of Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China
2. Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 China
3. Tiangong University Tianjin 300387 China
4. School of Physics and Astronomy University of Nottingham Nottingham NG7 2RD UK
5. Department of Physics University at Buffalo State University of New York Buffalo NY 14260 USA
6. Frantsevich Institute for Problems of Materials Science The National Academy of Sciences of Ukraine, Chernivtsi Branch Chernivtsi 58001 Ukraine
7. Beijing Academy of Quantum Information Sciences Beijing 100193 China