2 research outputs found
The metallic transport of (TMTSF)_2X organic conductors close to the superconducting phase
Comparing resistivity data of quasi-one dimensional superconductors
(TMTSF)_2PF_6 and (TMTSF)_2ClO_4 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
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 DFT calculations implying methyl group hyperconjugation in the
TMTSF molecule. In this low temperature regime, both materials exhibit for rc a
temperature dependence aT + bT^2. Taking into account the strong pressure
dependence of the anisotropy, the T-linear rc is found to correlate with the
suppression of the superconducting Tc, in close analogy with ra data. This work
is revealing the domain of existence of the 3D 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
Superconductivity and antiferromagnetism as interfering orders in organic conductors
Superconductivity in the Bechgaard salts series of quasi-one-dimensional
organic conductors occurs on the verge of spin-density-wave ordering when
hydrostatic pressure is applied. The sequence of instabilities is intimately
connected to normal state anomalies in various quantities like the temperature
dependence of electrical transport and nuclear spin-lattice relaxation rate. We
discuss how such a connection takes its origin in the interference between the
different pairing mechanisms responsible for antiferromagnetism and
superconductivity, a duo that can be comprehended in terms of a weak coupling
renormalization group theory. The recent developments along this line of though
are presented in relation to experiments.Comment: 11 pages, 6 figure