Molecular-dynamics study of collective modes and dislocation ordering in mismatched overlayers

Abstract
A molecular-dynamics study of the finite-length Frenkel-Kontorova model is presented. A dislocation depinning and ordering transition driven by soliton interactions is described. Complete phonon and collective-soliton-mode dispersion relations are determined for both well-ordered and pinned-disordered soliton arrays. Local modes, and zone folding due to phonon-soliton scattering, are identified. Possible applications of these results to experimental systems are suggested.