1. Center for Crystal R&D; Key Lab of Functional Crystals and Laser Technology of Chinese Academy of Sciences; Technical Institute of Physics and Chemistry; Chinese Academy of Sciences; Beijing 100190 China
2. University of Chinese Academy of Sciences; Beijing 100049 P. R. China
3. School of Physics and Wuhan National High Magnetic Field Center; Huazhong University of Science and Technology; Wuhan 430074 China
4. Key Laboratory of Cryogenics; Technical Institute of Physics and Chemistry; Chinese Academy of Sciences; Beijing 100190 China
5. Beijing Synchrotron Radiation Facility; Institute of High Energy Physics; Chinese Academy of Sciences; Beijing 100049 China
6. School of Earth and Space Sciences; Peking University; Beijing 100871 China