title: The metallic transport of (TMTSF)2X organic conductors close to the superconducting phase.
abstract: Comparing resistivity data of the quasi-one-dimensional superconductors (TMTSF)2PF6 and (TMTSF)2ClO4 along the least conducting c(⋆)-axis and along the high conductivity a-axis as a function of temperature and pressure, a low temperature regime is observed in which a unique scattering time governs the transport along both directions of these anisotropic conductors. However, the pressure dependence of the anisotropy implies a large pressure dependence of the interlayer coupling. This is in agreement with the results of first-principles density functional theory calculations implying methyl group hyperconjugation in the TMTSF molecule. In this low temperature regime, both materials exhibit for ρ(c) a temperature dependence aT + bT(2). Taking into account the strong pressure dependence of the anisotropy, the T-linear ρ(c) is found to correlate with the suppression of the superconducting Tc, in close analogy with ρ(a) data. This work reveals the domain of existence of the three-dimensional coherent regime in the generic (TMTSF)2X phase diagram and provides further support for the correlation between T-linear resistivity and superconductivity in non-conventional superconductors.
authors.affiliation: Laboratoire de Physique des Solides, UMR 8502 CNRS Université Paris-Sud, 91405 Orsay, France.
authors.forename: P
authors.initials: P
authors.lastname: Auban-Senzier
authors.forename: D
authors.initials: D
authors.lastname: Jérome
authors.forename: N
authors.initials: N
authors.lastname: Doiron-Leyraud
authors.forename: S
authors.initials: S
authors.lastname: René de Cotret
authors.forename: A
authors.initials: A
authors.lastname: Sedeki
authors.forename: C
authors.initials: C
authors.lastname: Bourbonnais
authors.forename: L
authors.initials: L
authors.lastname: Taillefer
authors.forename: P
authors.initials: P
authors.lastname: Alemany
authors.forename: E
authors.initials: E
authors.lastname: Canadell
authors.forename: K
authors.initials: K
authors.lastname: Bechgaard