1. State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano‐optoelectronics School of Physics Peking University Beijing 100871 P. R. China
2. State Key Laboratory of Integrated Optoelectronics College of Electronic Science and Engineering Jilin University Changchun 130012 P. R. China
3. Electron Microscopy Laboratory School of Physics Peking University Beijing 100871 P. R. China
4. Collaborative Innovation Center of Quantum Matter Beijing 100871 P. R. China