Theory of Thermal Conductivity in YBa_2Cu_3O_{7-\delta}

TL;DR

This paper models the electronic thermal conductivity in YBa_2Cu_3O_{7-\delta} superconductors, considering impurity and spin fluctuation scattering, and compares theoretical results with experimental data to understand heat transport mechanisms.

Contribution

It provides a theoretical framework for electronic thermal conductivity in d-wave superconductors, incorporating impurity and inelastic scattering effects, and analyzes experimental observations.

Findings

Phonons dominate heat transport near T_c.

Electrons contribute to the peak in thermal conductivity in clean samples.

Peak position varies nonmonotonically with disorder.

Abstract

We calculate the electronic thermal conductivity in a d-wave superconductor, including both the effect of impurity scattering and inelastic scattering by antiferromagnetic spin fluctuations. We analyze existing experiments, particularly with regard to the question of the relative importance of electronic and phononic contributions to the heat current, and to the influence of disorder on low-temperature properties. We find that phonons dominate heat transport near T_c, but that electrons are responsible for most of the peak observed in clean samples, in agreement with a recent analysis of Krishana et al. In agreement with recent data on YBa_2(Cu_1-xZn_x)_3O_7-\delta the peak position is found to vary nonmonotonically with disorder.