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 Sciences, Beijing 100049, China
3. National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu 30076, Taiwan, ROC
4. Max Planck Institute for Chemical Physics of Solids, Dresden 01187, Germany
5. Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications of Hunan, Hunan Normal University, Changsha 410081, China
6. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China