1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
2. National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050051, China
3. Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
4. Department of Physics, Tsinghua University, Beijing 100084, China