1. School of Materials Science and Engineering, State Key Laboratory of Optoelectronic Materials and Technologies, Key Laboratory of Polymer Composite & Functional Materials, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, P. R. China
2. School of Physics, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, P. R. China
3. College of Science, Hangzhou Dianzi University, Hangzhou 310018, P. R. China
4. State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, P. R. China
5. School of Physics, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou 510275, P. R. China
6. Shanghai Research Center for Quantum Sciences, Shanghai 201315, China