1. School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan 430074, China
2. Department of Physics, Southeast University, Nanjing 211189, China
3. Laboratory
of Solid State Microstructures, Nanjing University, Nanjing 210093, China
4. Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
5. Collaborative
Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, China