MOSKALENKO, S. A.; LIBERMAN, M. A.; SNOKE, D. W.; DUMANOV, E. V.; RUSU, S. S.; CERBU, F.
(Institutul de Fizică Aplicată al AŞM, 2012)
The energy spectrum of the collective elementary excitations consists of two exciton-type branches (energy and quasienergy branches), each of them with an energy gap and a roton-type region, from the gapless optical plasmon ...