Coupling of superconductors through a half-metallic ferromagnet: Evidence for a long-range proximity effect

Here we examine the ferromagnetic/superconducting proximity effect in half-metallic ferromagnetic La0.7Ca0.3MnO₃ and high-Tc superconducting YBa₂Cu₃O₇ artificial structures. We have found experimental evidence for the coupling between superconducting layers through ferromagnetic spacers in superlattices. This is consistent with a long-range proximity effect in half-metal ferromagnet/d-wave superconductor structures.