1. Zernike Institute for Advanced MaterialsUniversity of Groningen Nijenborgh 4 Groningen 9747 AG the Netherlands
2. Institute of Physics IARWTH Aachen University Aachen 52074 Germany
3. JARA‐Institute: Energy‐Efficient Information Technology (Green IT)Forschungszentrum Jülich GmbH Jülich 52428 Germany