1. Center of Materials Science and Optoelectronics Engineering, College of Materials Science and Optoelectronic Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
2. College of Sino-Danish, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
3. Department of Dynamics and Transport in Quantum Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, Berlin, Germany
4. Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
5. Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
6. Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, P. R. China