1. Institute of Condensed
Matter Physics, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
2. Department of Physics and Astronomy, Interdisciplinary
Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark
3. Elettra—Sincrotrone Trieste S.C.p.A., 34149 Basovizza,
Trieste, Italy
4. IOM-CNR Laboratorio TASC, Area Science Park, 34149 Trieste, Italy
5. Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell, Oxford OX11 0QX, United Kingdom
6. Lehrstuhl
für Technische Physik, Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
7. Institut
für Physik, Technische Universität Chemnitz, 09126 Chemnitz, Germany
8. SUPA, School of
Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9AJ, United Kingdom
9. Department
of Physics, University of Trieste, 34128 Trieste, Italy