1. National Laboratory of Solid State Microstructures and School of Physics, Collaborative Innovation Center of Advanced Microstructures,
Nanjing University, Nanjing 210093, China.
2. Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices, Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education),
Renmin University of China, Beijing 100872, China.