1. Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing
100190, People’s Republic of China
2. Stewart Blusson Quantum Matter Institute, Department of Physics and Astronomy, University of British Columbia,
Vancouver V6T 1Z1, Canada
3. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803,
USA
4. Collaborative Innovation Center of Quantum Matter, Beijing 100871, People’s Republic of China
5. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, People’s Republic of China