1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences 1 , Beijing 100190, China
2. School of Physical Sciences, University of Chinese Academy of Sciences 2 , Beijing 100049, China
3. Songshan Lake Materials Laboratory 3 , Dongguan, Guangdong 523808, China
4. School of Physics and Optoelectronic Engineering, Shandong University of Technology 4 , Zibo 255000, China
5. Fujian Innovation Academy, Chinese Academy of Sciences 5 , Fuzhou, Fujian 350108, China
6. Department of Physics and Astronomy, University of Nevada 6 , Las Vegas, Nevada 89154, USA