1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
2. School of Physical Sciences, University of Chinese Academy of Science, Beijing 100049, China
3. Department of Electrical and Computer Engineering, University of Illinois, Urbana-Champaign 61820, Illinois, United States
4. School of Physical Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China
5. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
6. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China