1. School of Physics, Huazhong University of Science and Technology 1 , Wuhan, China
2. Institute of Magnetism 2 , Kyiv, Ukraine
3. Fachbereich Physik and Landesforschungszentrum OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserlautern-Landau 3 , Kaiserslautern, Germany
4. Faculty of Physics, University of Vienna 4 , Vienna, Austria