DYNAMICS OF MULTICOMPONENT SOLITONS IN PERTURBED LADDER LATTICES

摘要

We investigate the interplay between the longitudinal and lateral solitonic modes in perturbed ladder lattices in regard to the transmission of soliton wave packet. (1) In a longitudinal uniform field the lateral and longitudinal solitonic modes are shown to be independent. However, unlike in the unperturbed case the dynamics of soliton center of mass becomes confined within a finite spatial domain via the Bloch mechanism in the longitudinal direction and due to the transverse finiteness of the ladder in the lateral one. (2) We study the impact of the modified transverse bond on the longitudinal soliton dynamics and reveal that this imperfection might act on the soliton either as an attractive or a repulsive potential, depending on the sign of the transverse energy of the ingoing soliton. (3) The segment of zigzag-distributed on-site impurities cause the soliton mode-mode mixing. As a result the soliton exhibits rather complex two-dimensional dynamics accompanied by wave radiation which may give rise to soliton trapping. Nevertheless, under some specific conditions the soliton is able to bypass even the strong impurities slaloming between them.