1. Department of Physics Shanghai Key Laboratory of High Temperature Superconductors Shanghai University Shanghai 200444 China
2. Singapore Synchrotron Light Source (SSLS) National University of Singapore Singapore 117603 Singapore
3. Institute of Materials Research and Ring (IMRE) Agency for Science Technology and Research (A*STAR) 2 Fusionopolis Way, Innovis #08‐03 Singapore 138634 Singapore
4. Center for Quantum Science and Technology Department of Physics Shanghai University Shanghai 200444 China
5. Department of Physics & NANOlab Center of Excellence University of Antwerp Groenenborgerlaan 171 Antwerp B‐2020 Belgium
6. Department of Physics Faculty of Science National University of Singapore Singapore 117542 Singapore
7. Centre for Advanced 2D Materials and Graphene Research National University of Singapore Singapore 117546 Singapore