1. State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
2. College of Physics, Jilin University, Changchun 130012, China
3. Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
4. Beijing Synchrotron Radiation Laboratory, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039, China