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Optimization of Spin-triplet Supercurrent in Ferromagnetic Josephson Junctions



Benjamin James McMorran, Theresa Ginley, Julie Borchers, Brian Kirby, Brian B. Maranville, John Unguris


In the past year, several groups have observed evidence for long-range spin-triplet, supercurrent in Josephson junctions containing ferromagnetic (F) materials. In our work, the spin-triplet pair correlations are created by non-collinear magnetizations between a central Co/Ru/Co "synthetic antiferromagnet" (SAF) and two outer think F layers. Here we present data showing that the spin-triplet supercurrent is enhanced up to 20 times after our samples are subject to a large in-plane magnetizing field. This surprising result can be explained if the Co/Ru/Co SAF undergones a "spin-flop" transition, whereby the two Co layer magnetizations end up perpendicular to the magnetizations of the two think F layers. Direct experimental evidence for the spin-flop transition comes from scanning electron microscopy with polarization analysis and from spin-polorized neutron reflectometry.
Physical Review Letters


Josephson Junction, Supercurrent Effect, Spin-flop transition, Polarized neutron reflectivity, SEMPA


McMorran, B. , Ginley, T. , Borchers, J. , Kirby, B. , Maranville, B. and Unguris, J. (2012), Optimization of Spin-triplet Supercurrent in Ferromagnetic Josephson Junctions, Physical Review Letters, [online], (Accessed July 17, 2024)


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Created March 19, 2012, Updated October 12, 2021