Mixed order parameter symmetries in cuprate superconductors

TL;DR

This paper investigates the complex order parameter symmetries in cuprate superconductors using a two-band model, revealing how mixed d-wave and s-wave symmetries influence superconducting properties and magnetic field responses.

Contribution

It introduces a two-band model with coupled order parameters of different symmetries to explain recent experimental observations in cuprate superconductors.

Findings

Superconductivity is primarily d-wave with an induced s-wave component.

The model explains the inflection point in lambda_ab(T) dependence.

Interband interactions stabilize the mixed symmetry state.

Abstract

The recent observation of an inflection point in the temperature dependence of the in-plane magnetic field dependence (lambda_ab) is investigated within a two-band model with coupled order parameters of different symmetries. While the dominant order parameter has d-wave symmetry, the smaller one is of s-wave symmetry. Superconductivity is robust in the d-wave channel and induced via interband interactions in the s-wave subsystem.