1. National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional Materials College of Engineering and Applied Sciences Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210000 China
2. School of Physics Nanjing University Nanjing 210000 China
3. Center for High Pressure Science State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066000 China
4. Quantum Phase Electronic Center and Department of Applied Physics The University of Tokyo Tokyo 113‐8656 Japan
5. Institute for Solid State Physics The University of Tokyo 5‐1‐5 Kashiwanoha, Kashiwa Chiba 277‐8581 Japan
6. RIKEN Center for Emergent Matter Science Hirosawa 2‐1 Wako 351‐0198 Japan