1. Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
2. Institute of Energy, Hefei Comprehensive National Science Center, Hefei, Anhui 230031, P. R. China
3. State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
4. High Magnetic Field Laboratory (HMFL), Hefei Institutes of Physical Science, CAS, Hefei, Anhui, 230031, P. R. China
5. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China