1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences 1 , Beijing 100190, China
2. School of Materials Science and Opto-electronic Technology, University of Chinese Academy of Sciences 2 , Beijing 100049, China
3. School of Physical Sciences, University of Chinese Academy of Sciences 3 , Beijing 100049, China
4. Songshan Lake Materials Laboratory 4 , Dongguan, Guangdong 523808, China
5. College of Physics, Liaoning University 5 , Shenyang, Liaoning 110036, China