1. National Laboratory of Solid State Microstructures, School
of Electronic Science and Engineering, and Collaborative Innovation
Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
2. Department of Physics, Southeast University, Nanjing 211189, People’s Republic of China
3. Synergetic Innovation Center for Quantum
Effects and Applications (SICQEA), Hunan Normal University, Changsha 410081, China
4. Department
of Electronic Engineering and Materials Science and Technology Research
Center, The Chinese University of Hong Kong, Hong Kong SAR, People’s Republic of China