1. York-Nanjing Joint Center (YNJC) for Spintronics and Nanoengineering, School of Electronics Science and Engineering, Nanjing University, Nanjing 210093, China
2. Spintronics and Nanodevice Laboratory, Department of Electronics, University of York, York YO10 5DD, United Kingdom
3. Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
4. Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
5. Center of Electron Microscopy, State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
6. Magnetic Spectroscopy Group, Diamond Light Source, Didcot OX11 0DE, United Kingdom