STABILITIES OF SOLITONS, POLARONS AND BIPOLARONS IN DIVALENT-DOPED TRANSPOLYACETYLENE

The stabilities of solitons, polarons and bipolarons in divalent-doped trans-polyacetylene have been studied hy considering the impurity Cou lomb confinement as well as the electron-electron interactions in the framework of the tight-binding Peierls-Hubbard model. It was found tha t transitions between bipolarons and solitons and between bipolarons a nd polarons will take place under certain conditions. The calculated v alues of the energy transitions agree well with the experimental resul ts in the dilute Ca2+-doped trans-polyacetylene material. The stabilit y of excitations with respect to the impurity confinement and the elec tron-electron interactions have been discussed.