1. Moscow Institute of Physics and Technology; State University; 9 Institutskiy per. Dolgoprudny Moscow Region 141700 Russia
2. National University of Science and Technology MISIS; 4 Leninsky prosp. Moscow 119049 Russia
3. Institute of Solid State Physics (ISSP RAS); Chernogolovka Moscow Region 142432 Russia
4. Solid State Physics Department; Kazan Federal University; Kazan 420008 Russia
5. Skobeltsyn Institute of Nuclear Physics; Lomonosov Moscow State University; Moscow 119991 Russia
6. Faculty of Science and Technology and MESA+ Institute for Nanotechnology; University of Twente; Enschede 7500 AE The Netherlands
7. Physikalisches Institut; Karlsruhe Institute of Technology; Karlsruhe 76131 Germany