1. Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic
2. Institute of Physics, Albert Ludwig University of Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
3. Institute of Physics, Czech Academy of Sciences, Cukrovarnická 10, CZ-162 00 Praha 6, Czech Republic
4. Institute of Physics II B, RWTH Aachen University, 52074 Aachen, Germany
5. Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Jülich Germany
6. Faculty of Mathematics and Natural Sciences, Institute of Physics II, University of Cologne, 50937 Cologne, Germany
7. Peter Grünberg Institut (Cryo-Lab), Forschungszentrum Jülich, JülichGermany
8. Fundamentals of Future Information Technology, Jülich Aachen Research Alliance (JARA), Jülich, Germany
9. Institute of Physics IV A, RWTH Aachen University, Aachen, Germany
10. RCPTM, Palacky University, Šlechtitelu 27, 783 71 Olomouc, Czech Republic