1. Experimentelle Physik 2, Technische Universität Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
2. Ioffe Institute, Politekhnycheskaya 26, 194021 St. Petersburg, Russia
3. Department of Theoretical Physics, V. E. Lashkaryov Institute of Semiconductor Physics, Pr. Nauky 41, 03028 Kyiv, Ukraine
4. Raith GmbH, Konrad-Adenauer-Allee 8, 44263 Dortmund, Germany
5. School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
6. LAUM, CNRS UMR 6613, Le Mans Université, 72085 Le Mans, France