Journal of Low Temperature Physics

, Volume 147, Issue 3, pp 457–476

Symmetries of Pairing Correlations in Superconductor–Ferromagnet Nanostructures

  • M. Eschrig
  • T. Löfwander
  • T. Champel
  • J. C. Cuevas
  • J. Kopu
  • Gerd Schön
Article

DOI: 10.1007/s10909-007-9329-6

Cite this article as:
Eschrig, M., Löfwander, T., Champel, T. et al. J Low Temp Phys (2007) 147: 457. doi:10.1007/s10909-007-9329-6

Using selection rules imposed by the Pauli principle, we classify pairing correlations according to their symmetry properties with respect to spin, momentum, and energy. We observe that inhomogeneity always leads to mixing of even- and odd-energy pairing components. We investigate the superconducting pairing correlations present near interfaces between superconductors and ferromagnets, with focus on clean systems consisting of singlet superconductors and either weak or half-metallic ferromagnets. Spin-active scattering in the interface region induces all of the possible symmetry components. In particular, the long-range equal-spin pairing correlations have odd-frequency s-wave and even-frequency p-wave components of comparable magnitudes. We also analyze the Josephson current through a half-metal. We find analytic expressions and a universality in the temperature dependence of the critical current in the tunneling limit.

Pacs Numbers

74.45.+c74.20.Rp74.50.+r

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • M. Eschrig
    • 1
  • T. Löfwander
    • 1
  • T. Champel
    • 1
    • 3
  • J. C. Cuevas
    • 1
    • 2
    • 4
  • J. Kopu
    • 1
  • Gerd Schön
    • 1
    • 2
  1. 1.Institut für Theoretische Festkörperphysik and DFG-Center for Functional NanostructuresUniversität KarlsruheKarlsruheGermany
  2. 2.Forschungszentrum KarlsruheInstitut für NanotechnologieKarlsruheGermany
  3. 3.Laboratoire de Physique et Modélisation des Milieux CondensésC.N.R.S.Grenoble CedexFrance
  4. 4.Departamento de Física Teórica de la Materia Condensada C-V, Facultad de CienciasUniversidad Autónoma de MadridMadridSpain