1. School of Materials Science and Engineering; Shenzhen Graduate School; Harbin Institute of Technology; Shenzhen 518055 P. R. China
2. Department of Applied Physics; The Hong Kong Polytechnic University; Hung Hom Hong Kong 999077 P. R. China
3. Department of Physics; The Hong Kong University of Science and Technology; Clear Water Bay Hong Kong 999077 P. R. China
4. Fachbereich Physik; Philipps Universitӓt Marburg; Marburg Germany
5. Hubei Zhongpu Union Medical Science and Technology Co., Ltd; Wuhan P. R. China
6. CIC Biomagune; San Sebastian Spain
7. Materials Science and Technology Division; Oak Ridge National Laboratory; Oak Ridge TN 37831 USA
8. Shenzhen Research Institute; The Hong Kong Polytechnic University; Shenzhen 518055 P. R. China