1. State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Micro‐System and Information Technology Chinese Academy of Sciences Shanghai 200050 P. R. China
2. University of Chinese Academy of Sciences Beijing 100029 P. R. China
3. Fronier Institute of Chip and System Fudan University Shanghai 20048 P. R. China
4. Department of Physics Graduate School of Science and Technology Gunma University Maebashi 3718510 Japan
5. Key Laboratory of Microelectronics Devices and Integrated Technology The Institute of Microelectronics Chinese Academy of Sciences IMECAS Beijing 100029 P. R. China