1. Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
2. Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
3. Instruments Center for Physical Science, University of Science and Technology of China, Hefei, Anhui 230026, China
4. Department of Physics, School of Physics, Hefei University of Technology, Hefei 230009, China
5. Department of Physics, University of Science and Technology of China, Hefei 230026, China