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 Prospect., 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. Laboratoire de Physique et d'Etudes des Materiaux, ESPCI-ParisTech, CNRS and UPMC Univ Paris 6 - UMR 8213, 10 rue Vauquelin, Paris 75005, France