Fluctuating spin density wave conduction in (TMTSF)₂X organic superconductors

¹ Laboratoire de Physique des Solides, UMR 8502 CNRS Université Paris-Sud - 91405 Orsay, France, EU
² Department of Chemistry, H.C. Ørsted Institute - Copenhagen, Denmark, EU

^a senzier@lps.u-psud.fr

Received: 29 September 2010
Accepted: 3 March 2011

Abstract

Transport measurements along the least conducting direction of the organic superconductors (TMTSF)₂PF₆ and (TMTSF)₂ClO₄ reveal a pronounced sublinear temperature dependence visible up to about four times the superconducting T_c either when pressure is close to the critical pressure for superconductivity in (TMTSF)₂PF₆ or under ambient pressure in (TMTSF)₂ClO₄ and ClO₄-ReO₄ solid solutions. Given the linear temperature dependence of the single-particle scattering in the metallic state derived from a previous investigation, the excess conduction insensitive to magnetic field but suppressed by lattice defects in the solid solution has been ascribed to sliding of fluctuating spin density waves in the vicinity of the antiferromagnetic order. This is the first observation of fluctuating spin density waves contributing to conduction.