1. College of Materials Science and Engineering, Kunming University of Science and Technology, 121 Street, Wenchang Road 68, Kunming 650093, China
2. Southwestern Institute of Physics, Huangjing Road 5, Chengdu 610041, China
3. Beijing Key Laboratory of Cryo-Biomedical Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China