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Suppression of Giant Magnetoresistance by a superconducting contact

F. Taddei·S. Sanvito·J. H. Jefferson·C. J. Lambert
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Abstract

We predict that current perpendicular to the plane (CPP) giant magnetoresistance (GMR) in a phase-coherent magnetic multilayer is suppressed when one of the contacts is superconducting. This is a consequence of a superconductivity-induced magneto-resistive (SMR) effect, whereby the conductance of the ferromagnetically aligned state is drastically reduced by superconductivity. To demonstrate this effect, we compute the GMR ratio of clean (Cu/Co)_nCu and (Cu/Co)_nPb multilayers, described by an ab-initio spd tight binding Hamiltonian. By analyzing a simpler model with two orbitals per site, we also show that the suppression survives in the presence of elastic scattering by impurities.

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F. Taddei, S. Sanvito, J. H. Jefferson, C. J. Lambert. 1999-01-29. Suppression of Giant Magnetoresistance by a superconducting contact. https://doi.org/10.1103/physrevlett.82.4938

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