1. Van ’t Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
2. FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG Amsterdam, The Netherlands
3. Institut für Textiltechnik, RWTH Aachen University, Otto-Blumenthal-Strasse 1, 52074 Aachen, Germany
4. Peter Grünberg Institute, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany