On Dynamics of Soliton Excitations in Coupled Chains

Abstract

Effects of interchain coupling on soliton dynamics are studied analytically based on the model describing, e . g ., ferromagnet chains with planar anisotropy or DNA double helices. In the framework of the perturbation theory the interaction of solitons belonging to different chains is investigated, a coupling constant being a small parameter. In particular, the interaction energy of the solitons is calculated, and it is demonstrated analytically that two slow solitons can form a bound state. Some radiative effects accompanying the soliton bound-state dynamics are considered by means of the perturbation theory based on the inverse scattering technique. It is also demonstrated that the slightly excited bound state of the solitons emits the longitudinal vibrations in the framework of a more general model used in the DNA theory.