Fc. Lavarda et al., Soliton clusters inducing insulator-to-metal transition in polyacetylene: a Su-Schrieffer-Heeger model study, SYNTH METAL, 123(2), 2001, pp. 211-215
The Su-Schrieffer-Heeger (SSH) Hamiltonian has been one of most used models
to study the electronic structure of polyacetylene (PA) chains. It has bee
n reported in the literature that in the SSH framework a disordered soliton
distribution can not produce a metallic regime. However, in this work (usi
ng the same SSH model and parameters) we show that this is possible. The ne
cessary conditions for true metals (non-vanishing density of states and ext
ended wavefunctions around the Fermi level) are obtained for soliton concen
tration higher than 6% through soliton segregation (clustering). These resu
lts are consistent with recent experimental data supporting disorder as an
essential mechanism behind the high conductivity of conducting polymers. (C
) 2001 Elsevier Science B.V. All rights reserved.