Towards a consistent picture for quasi-1D organic superconductors

TL;DR

This paper investigates the relationship between non-Fermi-liquid behavior, antiferromagnetic fluctuations, and superconductivity in quasi-1D organic superconductors, suggesting a common origin for anomalous scattering and pairing mechanisms.

Contribution

It demonstrates a correlation between antiferromagnetic fluctuations, resistivity behavior, and superconductivity, proposing a unified understanding of their interplay.

Findings

Resistivity linear term A vanishes as Tc approaches zero.

Antiferromagnetic fluctuations correlate with the non-Fermi-liquid resistivity component.

Similar mechanisms may be present in iron-pnictide superconductors.

Abstract

The electrical resistivity of the quasi-1D organic superconductor (TMTSF)2PF6 was recently measured at low temperature from the critical pressure needed to suppress the spin-density-wave state up to a pressure where superconductivity has almost disappeared. This data revealed a direct correlation between the onset of superconductivity at Tc and the strength of a non-Fermi-liquid linear term in the normal-state resistivity, going as r(T) = r0 + AT + BT2 at low temperature, so that A goes to 0 as Tc goes to 0. Here we show that the contribution of low-frequency antiferromagnetic fluctuations to the spin-lattice relaxation rate is also correlated with this non-Fermi-liquid term AT in the resistivity. These correlations suggest that anomalous scattering and pairing have a common origin, both rooted in the low-frequency antiferromagnetic fluctuations measured by NMR. A similar situation may also prevail in the recently-discovered iron-pnictide superconductors.