Soliton confinement in crystalline polyacetylene

The effects of interchain coupling on soliton confinement in crystalline polyacetylene are considered. The analysis of Baeriswyl and Maki on the confinement problem involving two solitons on different ${\left(\mathrm{CH}\right)}_x$ chains is extended to the case of two charged solitons on the same chain. Owing to the mutual repulsion between two charged solitons and the confinement effect due to interchain coupling, there exists a equilibrium confinement distance $2x_0$ between two solitons. The value of $2x_0$ is estimated to range between $3\xi$ and $4\xi$ where $\xi$ is the width of a soliton. A detailed study of the problem employing Green's functions in the coordinate representation is presented.