New Electronic States Localized at a Soliton in the Su-Schrieffer-Heeger Model

Abstract

New electronic localized states are analytically determined around a soliton. One of them has the energy lower than the bottom of the valence band and the other higher than the top of the conduction band. They are induced by the acoustic component of the order parameter in the first order Hamiltonian with respect to the ratio between the lattice constant and the soliton width. Usual perturbation procedure is vastly modified to obtain the states. Their energies agree fairly well with numerical simulation works, which have first indicated these levels.