Effects of the impurity potential on the band structure of doped trans-polyacetylene

Abstract

In order to understand the drastic effect of impurity doping on the transport properties of polyacetylene, the authors investigate in detail how the impurity ion potential alone affects the band structure of electrons and the order parameter in doped polyacetylene by a self-consistent numerical calculation based upon the Su-Schrieffer-Heeger Hamiltonian plus the impurity potential. Their results show that the potential has only a small effect on gap closure, which is mainly determined by the larger overlap between the electronic wavefunctions in the nearest soliton states. They also find that the order parameter does not go to zero in the heavily doped region where there is no gap, and it is almost unaffected by the impurity potential.