1. State Key Laboratory of Surface Physics and Department of Physics
2. Fudan University
3. Shanghai 200433
4. China
5. Department of Physics and Astronomy
6. University of California
7. Irvine
8. USA
9. National Laboratory of Solid State Microstructures and College of Engineering and Applied Sciences
10. Nanjing University
11. Nanjing 210093
12. Department of Chemical Engineering and Materials Sciecence
13. High Magnetic Field Laboratory
14. Chinese Academy of Science
15. Hefei 230031
16. Collaborative Innovation Center of Advanced Microstructures