1. Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences Beijing 100190 China
2. Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 China
3. Ningbo Institute of Materials Technology & Engineering Chinese Academy of Sciences Ningbo 315201 China
4. School of Physical Sciences University of Chinese Academy of Sciences Beijing 100190 China
5. Physics Department Shanghai Key Laboratory of High Temperature Superconductors Shanghai University Shanghai 200444 China
6. Songshan Lake Materials Laboratory Dongguan Guangdong 523808 China
7. School of Physics and Microelectronics Zhengzhou University Zhengzhou 450001 China
8. Institute of Materials Research and Engineering A*STAR 2 Fusionopolis Way Singapore 138634 Singapore
9. Department of Physics National University of Singapore 2 Science Drive 3 Singapore 117551 Singapore