Limits for Metallic Conductivity in Conducting Polymers

摘要: The temperature ( $T$) dependent dc conductivity ${\ensuremath{\sigma}}_{\mathrm{DC}}$) (down to 20 mK) and dielectric function at optical frequencies (0.002--6 eV) 6.5 GHz are used probe the inhomogeneous disorder-driven insulator-metal transition in conducting polymers. A correlation between large low $T$ ${\ensuremath{\sigma}}_{\mathrm{DC}}$ presence of a small fraction carrier density delocalized with long transport times $g{10}^{\ensuremath{-}13}\mathrm{s}$) indicates that metallic is due only charge carriers. achievable for these systems when entire participates estimated surpass copper.