Angular dependence of the superconducting transition temperature in ferromagnet-superconductor-ferromagnet trilayers

Phys Rev Lett. 2010 Nov 12;105(20):207002. doi: 10.1103/PhysRevLett.105.207002. Epub 2010 Nov 10.

Abstract

The superconducting transition temperature T(c) of a ferromagnet (F)-superconductor (S)-ferromagnet trilayer depends on the mutual orientation of the magnetic moments of the F layers. This effect has been previously observed in F/S/F systems as a T(c) difference between parallel and antiparallel configurations of the F layers. Here we report measurements of T(c) in CuNi/Nb/CuNi trilayers as a function of the angle between the magnetic moments of the CuNi ferromagnets. The observed angular dependence of T(c) is in qualitative agreement with a F/S proximity theory that accounts for the odd triplet component of the condensate predicted to arise for noncollinear orientation of the magnetic moments of the F layers.