Metal-insulator transition in highly conducting oriented polymers

TL;DR

This paper models highly conducting oriented polymers with fibril structures as a lattice of disordered metallic wires, using a non-linear sigma model to analyze the metal-insulator transition based on interwire coupling and cross-link concentration.

Contribution

It introduces a novel lattice model for conducting polymers and applies a non-linear sigma model to study the metal-insulator transition.

Findings

Transition depends on cross-link concentration

Transition influenced by interwire coupling strength

Number of polymer chains affects transition point

Abstract

We suggest that highly conducting oriented polymers with a fibril structure can be modeled by a regular lattice of disordered metallic wires with a random first-neighbor interwire coupling which mimics the cross-links between fibrils. We show that such a model can be described by a non-linear sigma model. Within a one-loop self-consistent approximation, we determine the position of the metal-insulator transition as a function of interwire cross-links concentration, interwire coupling and number of polymer chains in a wire.