title: Theory of multiband superconductivity in spin-density-wave metals.
abstract: We study the emergence of multiband superconductivity with s- and d-wave symmetry on the background of a 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 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.
authors.affiliation: Institut für Theoretische Physik III, Ruhr-Universität Bochum, D-44801 Bochum, Germany.
authors.forename: J-P
authors.initials: JP
authors.lastname: Ismer
authors.forename: Ilya
authors.initials: I
authors.lastname: Eremin
authors.forename: Enrico
authors.initials: E
authors.lastname: Rossi
authors.forename: Dirk K
authors.initials: DK
authors.lastname: Morr
authors.forename: G
authors.initials: G
authors.lastname: Blumberg