[1] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan,250100, China
[2] Peter Grünberg Institute, Forschungszentrum Jülich, Jülich,52425, Germany
[3] Department of Physics, RWTH Aachen University, Aachen,52056, Germany
[4] Institute of Physics, Johannes Gutenberg University Mainz, Mainz,55099, Germany