1. Department of Physics, Harbin Institute of Technology, Harbin 150080, China
2. Condensed Matter Science and Technology Institute, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
3. College of Materials Science and Engineering, Liaocheng University, Liaocheng 252059, China
4. School of Physics, Shandong University, Jinan 250100, China
5. School of Civil Engineering, Harbin Institute of Technology, Harbin 150001, China
6. Department of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA