METALLIC MICROWAVE DIELECTRIC RESPONSE OF POLYACETYLENE

Using the dielectric constant and conductivity at microwave frequency, we study the differences between highly conducting polyacetylenes and standard metals. We report that the microwave dielectric constant at room temperature for heavily-iodine-doped Tsukamoto polyacetylene film s is negative and of record size. This demonstrates that the highly co nducting state is metallic despite the decrease in conductivity with d ecreasing temperature. The anomalously long transport time is attribut ed to suppression of both phonon and impurity backward scattering in a structure with an open Fermi surface. We analyze the temperature-depe ndent data using a model of three-dimensional metallic fiber segments coupled by weak links within which one-dimensional localization effect s occur.