1. Condensed
Matter Science and Technology Institute, Harbin Institute of Technology, Harbin 150080, China
2. Department
of Physics, Harbin Institute of Technology, Harbin 150001, China
3. Division
of Cardiology, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, China
4. Department
of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States