Influence of carrier lifetime on quantum criticality and superconducting Tc of (TMTSF)_2ClO_4

Abstract

This work presents and analyzes electrical resistivity data on the organic superconductor (TMTSF)${}_2$ClO${}_4$ and their anion substituted alloys (TMTSF)${}_2$(ClO${}_4$)${}_{1-x}$(ReO${}_4$)${}_x$ along the least conducting $c^{\star }$ axis. Nonmagnetic disorder introduced by finite size domains of anion ordering on non Fermi liquid character of resistivity is investigated near the conditions of quantum criticality. The evolution of the $T$-linear resistivity term with anion disorder shows a limited decrease in contrast with the complete suppression of the critical temperature $T_c$ as expected for unconventional superconductivity beyond a threshold value of $x$. The resulting breakdown of scaling between both quantities is compared to the theoretical predictions of a linearized Boltzmann equation combined to the scaling theory of umklapp scattering in the presence of disorder induced pair-breaking for the carriers.

13 pages, 8 figures