Influence of spin relaxation length on lateral double superconductor/ferromagnet/superconductor junctions

Abstract

We study the spin dependent transport at the junctions between two superconductingNb leads connected by two ferromagnetic NiFe bars in parallel, which have various separations. The separation distance l between NiFe bars was varied from 150 to 700 nm to study the spin relaxation effect in Nb. In small l (150 and 250 nm) samples, a spin-valve-like behavior related to the inverse proximity effect was observed, which manifest itself as charge accumulation due to spin imbalance near the interface. However, for samples with large l, the spin-valve behavior vanishes and the anisotropic magnetoresistance effect dominates.