1. CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, P.R. China
2. University of Chinese Academy of Sciences, Beijing 100049, P.R. China
3. Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P.R. China
4. Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion, Synergetic Innovation of Quantum Information & Quantum Technology, School of Chemistry and Materials Sciences, and CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230026, P.R. China
5. National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Strongly coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230029, P.R. China