Institution: | [1]School of Physics, University of Chinese Academy of Sciences, PO Box 4588, Beijing 100049; [2]Laboratory of Quantum Engineering and Quantum Materials, SPTE, South China Normal University, Guangzhou 510006; [3]State Key Laboratory for Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084; [4]Department of Physics, Capital Normal University, Beijing 100037 |