1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
2. School of Integrated Circuits, Guangdong University of Technology, Guangzhou 510006, China
3. Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
4. Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences (IMECAS), Beijing 100029, China
5. York-Nanjing International Center of Spintronics (YNICS), York University, York YO10 3LT, U.K.