1. Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, China
2. Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China
3. School of Physics and Optoelectronic Engineering, Anhui University, Hefei, Anhui 230601, China
4. Department of Physics and Key Laboratory of Strongly-Coupled Quantum Matter Physics (CAS), University of Science and Technology of China, Hefei, Anhui 230026, China
5. Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, Jiangsu 210093, China