1. Quantum Solid State Physics, KU Leuven, Leuven 3001, Belgium
2. Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
3. Imec Vzw (Interuniversitair Micro-Electronica Centrum), Leuven 3001, Belgium
4. Department of Chemistry, Division of Molecular Design and Synthesis, KU Leuven, Leuven 3001, Belgium
5. II. Institute of Physics, University of Göttingen, Göttingen 37077, Germany
6. Institut fur̈ Experimentalphysik, Universität Hamburg, Hamburg 22761, Germany
7. Laboratory of Quantum Optics, University of Nova Gorica, Vipavska 11c, Ajdovščina SI-5270, Slovenia
8. ETSF and Dipartimento di Fisica “Aldo Pontremoli”, Università Degli Studi di Milano, Via Celoria, 16, Milano I-20133, Italy
9. Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, Trieste 34149, Italy
10. Department of Chemistry, Division of Molecular Imaging and Photonics, KU Leuven, Leuven 3001, Belgium