1. Beijing Key Laboratory for Microwave Sensing and Security ApplicationsSchool of Electronic and Information EngineeringBeihang University Beijing 100083 China
2. Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences Beijing 100190 China
3. School of Physical SciencesUniversity of Chinese Academy of Sciences Beijing 100049 China
4. Fert Beijing Institute and School of MicroelectronicsBeihang University Beijing 100191 China
5. Beihang‐Goertek Joint Microelectronics InstituteQingdao Research InstituteBeihang University Qingdao 266000 China