گذار نيم رسانا به فلز در پلي استيلن )trans-PA( (نقش ساليتونهاي همبسته )

In this study the nature of transition to metallic regime in trans-polyacetylene (trans-PA) is investigated. Based on Su-Schrieffer-Heeger (SSH) model and the use of Continued - Fraction Representation (CFR) as well as Lanczos algorithm procedure, we studied the effects of some selected soliton distributions on the semiconductor-to-metal transition in trans-PA.We found that: i) this transition occurs only when there exists a soliton sublattice in trans-PA, ii) disordered soliton distributions and soliton clustering are the origin of the metallic transition in trans-PA, that is consistent with the experimental data. Our results show that in the presence of correlation between solitons, the disorder in accompanying single soliton distributions plays a crucial role in inducing the transition to metallic regime, so that in contrast to Andersonʹs localization theorem, the electronic states near the Fermi level are extended, that is the most significant criteria for the metallic regime.