POSSIBILITY OF SUPERCONDUCTING PRECURSOR EFFECTS IN QUASI-ONE-DIMENSIONAL ORGANIC CONDUCTORS - THEORY AND EXPERIMENTS

Report an investigation of the temperature dependence of the conductivity and conductivity anisotropy in the single-chain quasi-one-dimensional organic conductor (TMTSF)//2PF//6 under 12 kbar between 200 K and the superconducting transition temperature. An interpretation of the data in terms of a single-particle conduction mechanism would lead to a huge mean free path of about 3,000 A at helium temperature which seems rather hard to accept. Instead, we proposed an interpretation based on superconducting fluctuations induced paraconductivity. The calculation is performed with a time dependent Landau-Ginzburg theory. The satisfying quantitative agreement between the theoretical model and the experimental data points out the dominant role of superconducting fluctuations in this conductor up to about 40 K. The theory shows that unlike conductivity the susceptibility is not significantly enhanced by the fluctuations in the same temperature domain.