1. M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 18 S. Kovalevskaya Str., Ekaterinburg 620108, Russia
2. Ural Federal University, 19 Mira Str., Ekaterinburg 620002, Russia
3. A. V. Rzhanov Institute of Semiconductor Physics of Siberian Branch of Russian Academy of Sciences, 13 Lavrentyev Ave., Novosibirsk 630090, Russia