1. Department of Physics and Beijing Key Laboratory of Opto-Electronic Functional Materials & Micro-Nano Devices, Renmin University of China 1 , Beijing 100872, China
2. Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin University of China 2 , Beijing 100872, China
3. Institute of Physics, Chinese Academy of Sciences 3 , 100190 Beijing, China
4. Songshan Lake Materials Laboratory 4 , Dongguan, Guangdong 523808, China
5. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences 5 , Beijing 100049, China