1. Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Amalienstrasse 54, 80799 Munich, Germany
2. neaspec GmbH, Bunsenstrasse 5, Martinsried, 82152 Munich, Germany
3. Department of Physics, Ludwig-Maximilians-Universität München, Schellingstr. 4, 80799 Munich, Germany
4. Center for Nanoscience (CeNS), Schellingstrasse 4, 80799 Munich, Germany
5. National Institute for Materials Science, Tsukuba, Japan
6. Donostia International Physics Center (DIPC), Paseo Manuel Lardizabal 4, 20018 Donostia-San Sebastián, Spain
7. Nanosystems Initiative Munich (NIM), and Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 Munich, Germany