1. School of Electronic and Information Engineering, Beihang University, Beijing 100191, China
2. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
4. Fert Beijing Institute, BDBC, and School of Microelectronics, Beihang University, Beijing 100191, China
5. Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute, Beihang University, Qingdao 266000, China