Multiband Superconductivity in Spin Density Wave Metals

TL;DR

This paper investigates how spin density wave order influences multiband superconductivity, revealing that SDW coherence factors modify the gap symmetry and that interband scattering stabilizes both s- and d-wave states, with s-wave being more suppressed as SDW increases.

Contribution

It demonstrates how SDW coherence factors alter superconducting gap symmetry and shows the differential suppression of s- and d-wave states with SDW strength in 2D systems.

Findings

SDW coherence factors renormalize the SC gap momentum dependence

Interband Cooper pair scattering stabilizes both s- and d-wave superconductivity

Increasing SDW order suppresses s-wave more than d-wave

Abstract

We study the emergence of multiband superconductivity with $s$- and $d-$wave symmetry on the background of spin density wave (SDW). We show that the SDW coherence factors renormalize the momentum dependence of the superconducting (SC) gap, yielding a SC state with an \emph{unconventional} s-wave symmetry. Interband Cooper pair scattering stabilizes superconductivity in both symmetries. With increasing SDW order, the s-wave state is more strongly suppressed than the d-wave state. Our results are universally applicable to two-dimensional systems with a commensurate SDW.