1. State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
2. State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China
3. Department of Geological Sciences, Stanford University, Stanford, California 94305, United States
4. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United State