Disorder and chain superconductivity in YBa_2Cu_3O_{7-\delta}

TL;DR

This paper investigates how chain disorder affects superconductivity in YBa_2Cu_3O_{7- ext{delta}}, showing that disorder causes pair-breaking and localization, with experimental data supporting the theoretical model.

Contribution

It introduces a proximity model to analyze chain disorder effects on superconductivity, incorporating hybridization and self-consistent T-matrix approximation for quantitative agreement.

Findings

Chain disorder causes pair-breaking and localization effects.

Transport anisotropy remains large despite oxygen vacancies.

Model aligns well with penetration depth and specific heat measurements.

Abstract

The effects of chain disorder on superconductivity in YBa_2Cu_3O_{7-\delta} are discussed within the context of a proximity model. Chain disorder causes both pair-breaking and localization. The hybridization of chain and plane wavefunctions reduces the importance of localization, so that the transport anisotropy remains large in the presence of a finite fraction $\delta$ of oxygen vacancies. Penetration depth and specific heat measurements probe the pair-breaking effects of chain disorder, and are discussed in detail at the level of the self-consistent T-matrix approximation. Quantitative agreement with these experiments is found when chain disorder is present.