1. Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
2. Laboratory for Mesoscopic Systems, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
3. CEITEC BUT, Brno University of Technology, 61200 Brno, Czech Republic
4. NanoSpin, Department of Applied Physics, Aalto University, P.O. Box 15100, FI-00076 Aalto, Finland
5. Laboratory for Magnetism and Interface Physics, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland
6. Helmholtz-Zentrum Berlin, 12489 Berlin, Germany
7. Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
8. Institute of Physics, Johannes Gutenberg University Mainz, 55128 Mainz, Germany