1. Physics Department, Moscow State Pedagogical University, Moscow 119991, Russia
2. National Research Centre “Kurchatov Institute,” Moscow 123128, Russia
3. Moscow Institute of Physics and Technology (State University), Dolgoprudny 141700, Russia
4. Departament d'Enginyeria Electrònica, Escola d'Enginyeria, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
5. Moscow Institute of Electronics and Mathematics, National Research University Higher School of Economics, Moscow 109028, Russia