Coherence and superconductivity in coupled one-dimensional chains: a case study of YBa${}_2$Cu${}_3$O${}_y$

Abstract

We report the infrared (IR) response of Cu-O chains in the high-$T_c$ superconductor YBa${}_2$Cu${}_3$O${}_y$ over the doping range spanning . We find evidence for a power law scaling at mid-IR frequencies consistent with predictions for Tomonaga-Luttinger liquid, thus supporting the notion of one-dimensional transport in the chains. We analyze the role of coupling to the CuO${}_2$ planes in establishing metallicity and superconductivity in disordered chain fragments.

4 pages, 3 figures