1. School of Physics and Electronic Science, Institute of Applied Physics, Guizhou Education University, Guiyang 550018, China
2. College of Mathematical and Physical Sciences, Anshun University, Guizhou 561000, China
3. Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Education University, Guiyang 550018, China
4. Faculty of Physics, University of Vienna, Wien 1090, Austria