1. School of Materials Science and Engineering Beihang University Beijing 100191 P. R. China
2. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190 P. R. China
3. CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Mechanics University of Science and Technology of China Hefei 230027 P. R. China
4. Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 P. R. China
5. State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University Weijin Road Tianjin CN‐300072 P. R. China
6. State Key Lab for Mesoscopic Physics and Frontiers Science Center for Nano‐Optoelectronics School of Physics Peking University Beijing 100871 P. R. China
7. College of Materials and Chemical Engineering Minjiang University Fuzhou 350108 P. R. China