1. Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
2. Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
3. University of Chinese Academy of Sciences, Beijing 100049, China
4. Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
5. Fusion Simulation Center, Peking University, Beijing 100871, China