Quantum corrections to solitons in polyacetylene

Abstract

The quantum corrections on the soliton in polyacetylene is studied within the continuum version of the Su, Schrieffer, and Heeger model. First, the optical-phonon spectrum in the presence of a soliton is determined. It is shown that the soliton generates two localized phonon modes; the one with $\omega =0\mathrm{}$ corresponds to the translation of the soliton, while the other with $\omega \simeq 0.8{\omega }_0$ is Raman active where ${\omega }_0$ is the optical-phonon frequency with $k=0\mathrm{}$. The quantum correction to the soliton energy $E_s$ is also calculated. We find the correction is rather important: $\delta E_s\simeq -\frac{1}{4}{E}_s$.