1. Institute of Applied Physics of the Russian Academy of Sciences, Ulyanova Street 46, 603950 Nizhny Novgorod, Russia
2. Institute of Continuous Media Mechanics, UB RAS, Academician Korolev Street 1, 614013 Perm, Russia
3. Department of Theoretical Physics, Perm State University, Bukirev Street 15, 614990 Perm, Russia