Very short mean free path in organic metals

Abstract

Organic metals exhibit a relatively high resistivity at ambient temperature and the mean free path l may be less than the molecular spacing. In one-dimensional metals like TTF-TCNQ, TMTSF₂X, and even doped polyacetylene, a symmetry argument provents linear coupling between the low-frequency librations and the electrons. In the two-dimensional organic metal BEDT-TTF₂I₃ linear coupling with the librons is possible, resulting in much greater resistivity. A very strong coupling with a very soft phonon of frequency 1 meV has been observed experimentally. The conductivity of the metallic state can be considerably less than Mott's minimum value, because of interband scattering.