1. College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, China
2. Department of Electrical and Microelectronic Engineering, Rochester Institute of Technology, Rochester, NY, USA
3. Department of Computer Science, University of California at Irvine, Irvine, CA, USA
4. School of Micronanotelectronics, Zhejiang University, Hangzhou, China
5. Witmem Company Ltd., Beijing, China
6. Fert Beijing Research Institute, School of Electronics and Information Engineering, Beihang University, Beijing, China
7. College of ISEE, Zhejiang University, Hangzhou, China