1. 2nd
Institute of Physics and JARA-FIT, RWTH Aachen University, 52074 Aachen, Germany
2. Peter
Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany
3. National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan