1. Laboratory for Solid State Physics, ETH Zürich, Otto-Stern-Weg. 1, CH-8093 Zürich, Switzerland
2. Department of Condensed Matter Physics, Masaryk University, Kotlářská 2, CZ-61137 Brno, Czech Republic
3. CEITEC, Masaryk University Kamenice 5, CZ-60177 Brno, Czech Republic
4. L-NESS, Department of Materials Science, Università di Milano-Bicocca, Via R. Cozzi 55, I-20125 Milano, Italy
5. L-NESS and Department of Physics, Politecnico di Milano, via Anzani 42, I-22100 Como, Italy
6. Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zürich, Auguste-Piccard-Hof 1, CH-8093 Zürich, Switzerland