1. Peter Grünberg Institute PGI-6, Forschungszentrum Jülich 1 , D-52425 Jülich, Germany
2. Fakultät für Physik, Universität Duisburg-Essen 2 , D-47057 Duisburg, Germany
3. Beijing Academy of Quantum Information Sciences 3 , Beijing 100193, China
4. Center for High Pressure Science and Technology Advanced Research 4 , Beijing 100094, China
5. State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences 5 , Shanghai 200050, China
6. Institute of Physics, Chinese Academy of Sciences 6 , Beijing 100190, China