We show measurements of the dynamical conductance of a device consisting of thin ferromagnetic cobalt strips having alternating stronger and weaker coercive fields, located less than a coherence length apart connecting two superconducting indium electrodes. At a bias lower than the superconducting gap the conductance is sensitive to the relative polarization of adjacent ferromagnetic strips. We find that the conductance is higher when the wire polarizations are parallel. The sign and magnitude of this effect are interpreted in terms of the balance between equal and opposite spin components of the superconducting order parameters at the interface.
|Physical Review B - Condensed Matter and Materials Physics
|Published - 8 Aug 2011