1. State Key Laboratory of Magnetism and 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 Sciences, Beijing 100049, China
3. Department of Physics, North Carolina State University, Raleigh, North Carolina 27695, United States
4. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China