1. Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
2. University of Science and Technology of China, Hefei 230026, China
3. Center for High Pressure Science and Technology Advanced Research, 1690 Cailun Road, Shanghai 201203, China
4. Istituto Nazionale di Ottica (CNR-INO) and European Laboratory for Non Linear Spectroscopy (LENS), 50019 Sesto Fiorentino, Italy
5. Centre for Science at Extreme Conditions, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom