1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences , Beijing , China
2. School of Physical Sciences, University of Chinese Academy of Sciences , Beijing , China
3. State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University , Beijing , China
4. School of Materials Science and Engineering, Tsinghua University , Beijing , China
5. New Cornerstone Science Laboratory, Frontier Science Center for Quantum Information , Beijing , China
6. Hefei National Laboratory , Hefei , China