Solitons with adjustable charge in a commensurate Peierls insulator

Abstract

We consider a one-dimensional electron gas with a half-filled band in which the electrons are coupled to both intersite and intrasite lattice distortions. In the region of parameter space in which both types of distortion develop nonzero expectation values, a new class of soliton which spontaneously breaks the charge conjugation symmetry of the model appears as the lowest-lying electronic excitation of the system. The soliton charge is a continuous function of the coupling constants.