1. York-Nanjing International Center of Spintronics (YNICS), Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Material, Jiangsu Procincial Key Laboratory for Nanotechnology, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China
2. Spintronics and Nanodevice laboratory, Department of Electronics, University of York, YO10 5DD, United Kingdom
3. National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
4. Department of Physics, University of York, YO10 5DD, United Kingdom
5. College of Communication Engineering, Chongqing University, Chongqing 400044, China