INSULATOR-METAL TRANSITION IN CONDUCTING POLYMERS - EFFECT OF RANDOMNESS

Calculations of a number of authors have shown that randomness of the soliton distribution would greatly decrease the dopant concentration r equired for the insulator-metal transition in polyacetylene. We show h ere that the pinning of the solitons to the dopant ions so restricts t heir motion that the concentration required for the transition is unaf fected by the allowed soliton motion at zero temperature. There may be some effect at higher temperatures and concentrations not far below t hat required to cause the transition due to the greater randomness und er those conditions.