1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
2. College of Sciences, Northeastern University, Shenyang 110819, China
3. Max Planck Institute for Microstructure Physics, 06120 Halle, Germany
4. Department of Physics, Beijing Technology and Business University, Beijing 100048, China
5. State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
6. Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China
7. Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Natural Materials & Micro-nano Devices, Renmin University of China, Beijing 100872, China