1. Institute of Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstrasse 15, 76131 Karlsruhe, Germany
2. Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology, Hermann-von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
3. Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
4. Centre Européen de Science Quantique, Institut de Science et d’Ingénierie Supramoléculaires, Université de Strasbourg, 8 allée Gaspard Monge, BP 70028, 67083 Strasbourg Cedex, France