1. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication
2. National Center for Nanoscience and Technology
3. Beijing, P. R. China
4. State Key Laboratory of Superlattices and Microstructures
5. Institute of Semiconductors
6. Chinese Academy of Sciences
7. Beijing, P.R. China
8. Synergetic Innovation Center of Quantum Information and Quantum Physics