1. Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science & Engineering, Beijing Institute of Technology, 5 Zhongguancun South Street, Haidian District, Beijing 100081, China
2. National Laboratory of Solid State Microstructures, School of Physics & Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
3. School of Physics, Beijing Institute of Technology, 5 Zhongguancun South Street, Haidian District, Beijing 100081, China
4. Wuhan National High Magnetic Field Center and Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, China