Localization softening in flexible conducting polymers

We study the conduction properties of polymers in relation to their structural rigidity, which is considered more explicitly by modeling polymers as semiflexible chains of length L. We characterize mechanical flexibility by the persistence length l(p) and evaluate electronic conductance for various l(p). It is found that in the absence of intrinsic disorder, the conductance exponentially decays with L/l(p), indicating that the flexibility allowing cross-links simply supplies disorder. When intrinsic disorder is present, the role of flexibility is differentiated depending on the disorder strength. A region is found to exist deep in the localized regime, where the polymer flexibility enhances the conductance, softening the localization.