1. Physical Science and Engineering Division King Abdullah University of Science and Technology Thuwal 23955–6900 Saudi Arabia
2. School of Advanced Materials and Nanotechnology Xidian University Xi'an 710126 China
3. Department of Materials Science and Engineering The Pennsylvania State University University Park PA 16802 USA
4. College of Intelligence Science and Technology National University of Defense Technology Changsha 410 073 China
5. Department of Physics and State Key Laboratory of Low‐Dimensional Quantum Physics Tsinghua University Beijing 100084 China
6. State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and Engineering Tsinghua University Beijing 100084 China
7. Department of Physics University of California at Berkeley Berkeley CA 94720 USA