1. Advanced Functional Materials Lab, Department of Physics, Changshu Institute of Technology, Changshu 215500, China
2. Information Physics Research Center, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
3. Department of Physics, Zhejiang University of Science and Technology, Hangzhou 310023, China
4. Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
5. Institute of Physics, Academia Sinica, Nankang, Taipei, R.O.C. Taiwan 11529
6. Department of Chemistry and Biochemistry, University of Berne, Freiestrasse 3, CH-3012 Berne, Switzerland
7. School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
8. Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China