1. College of Physics, Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, Key Laboratory of Photonics Materials and Technology in Universities of Shandong, and National Demonstration Center for Experimental Applied Physics Education, Qingdao University, Qingdao 266071, People’s Republic of China
2. Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, People’s Republic of China