Electromagnetic Absorption in an Anisotropic Layered Superconductor

TL;DR

This paper calculates the infrared conductivity tensor of layered superconductors with different order parameter symmetries, analyzing how optical absorption measurements can differentiate between anisotropic s-wave and d-wave states.

Contribution

It provides a theoretical comparison of optical absorption signatures for anisotropic s-wave and d-wave superconductors considering scattering effects.

Findings

Distinct absorption features for s-wave and d-wave symmetries

Scattering influences the optical conductivity signatures

Guidelines for experimental identification of order parameter symmetry

Abstract

We calculate the infrared conductivity tensor of a layered superconductor considering two different order parameter symmetries: strongly anisotropic $s$-wave with line nodes, and pure ($d_{x^2-y^2}$) $d$-wave. The calculations are performed within the quasiclassical theory of superconductivity and include the effects of non-magnetic scattering processes. We discuss to what extent measurements of the optical absorption can be relied upon to distinguish between these two order parameter symmetries.