1. Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California94025, United States
2. Sigray, Inc., Concord, California 94520, United States
3. Beijing Advanced Innovation Center for Materials Genome Engineering, Huairou Division, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
4. School of Physics, University of Chinese Academy of Sciences, Beijing100049, China
5. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing100049, China