Excitation and stability of bright and dark localised spin modes in ferromagnetic chains with on-site anisotropy

Abstract

An investigation of the evolution to localised states of various input spin distributions is presented, for a linear ferromagnetic chain with on-site anisotropy. A detailed study of the accessibility of bright solitary stationary states from a given input spin distribution is presented from both a discrete and a continuum point of view. Both nonlinear Schrödinger and modified regimes are encountered. Dark solitons, modulation instability for the discrete and continuum equations, a full discussion of the class of continuum solutions and a Lagrangian analysis are all presented here.