d-Wave Model for Microwave Response of High-Tc Superconductors

TL;DR

This paper presents a theoretical model for the microwave electromagnetic response of d-wave high-temperature superconductors, comparing predictions with experimental data and discussing implications for pairing mechanisms.

Contribution

It introduces a simple, comprehensive theory accounting for potential and inelastic scattering in d-wave superconductors and compares it with experimental microwave response data.

Findings

The theory fits penetration depth data well.

Discrepancies exist between predicted and observed low-temperature microwave conductivity.

Implications for d-wave pairing in cuprates are discussed.

Abstract

We develop a simple theory of the electromagnetic response of a d- wave superconductor in the presence of potential scatterers of arbitrary s-wave scattering strength and inelastic scattering by antiferromagnetic spin fluctuations. In the clean London limit, the conductivity of such a system may be expressed in "Drude" form, in terms of a frequency-averaged relaxation time. We compare predictions of the theory with recent data on YBCO and BSSCO crystals and on YBCO films. While fits to penetration depth measurements are promising, the low temperature behavior of the measured microwave conductivity appears to be in disagreement with our results. We discuss implications for d-wave pairing scenarios in the cuprate superconductors.