Intrinsic localized modes of bright and dark types in ferromagnetic Heisenberg chains

Abstract

We study the existence and properties of intrinsic localized spin-wave modes in one-dimensional, anisotropic, ferromagnetic Heisenberg chains. We show that stable dark localized modes can appear inside the linear spin-wave spectrum, and derive the conditions for the existence of these and bright-envelope modes. By exploiting the symmetry of the equations of motion we find localized modes that exist in a strong driving field and analyze their stability by molecular-dynamics simulations.