Enhancement of susceptibility and the electrical resistivity of organic metals with a small mean free path

The electronic mean free path of organic metals at ambient temperature is small, approximately one lattice constant.This small mean free path requires a reformulation of transport theory, and also gives rise to new physical effects. The gain susceptibility is enhanced over the Pauli value by approximately a factor of two, and the resistivity continues to follow a T²-law and does not saturate even when the mean free path becomes smaller than a lattice constant. A theory is described which accounts for these unusual effects. The theory is somewhat analogous to polaron theory and makes use of the quadratic nature of the electron-phonon coupling. The electrons are localized by 'phonon traps' accounting for the transition to a Curie-like behavior. Tunneling between these non-degenerate molecular sites gives rise to a T²-law with a coefficient close to that of the low-temperature state where the conductivity is metallic.