1. School of Physics and Electronics, Hunan University, Changsha 410082, People’s Republic of China
2. School of Physics, Nankai University, Tianjin 300071, People’s Republic of China
3. International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871, People’s Republic of China
4. Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, Hunan University, Changsha 410082, People’s Republic of China