The combination of superconducting and magnetic materials to create novelsuperconducting devices has been motivated by the discovery of Josephsoncritical current (Ics) oscillations as a function of magnetic layer thicknessand the demonstration of devices with switchable critical currents. However,none of the hybrid devices have shown any spintronic effects, such asspin-transfer torque, which are currently used in room-temperature magneticdevices, including spin-transfer torque random-access memory and spin-torquenano-oscillators. We have developed nanopillar Josephson junctions with aminimum feature size of 50 nm and magnetic barriers exhibiting magneticpseudo-spin-valve behavior at 4 K. These devices allow current-inducedmagnetization switching that results in 20-fold changes in Ics. Thecurrent-induced magnetic switching is consistent with spin-transfer torquemodels for room-temperature magnetic devices. Our work demonstrates thatdevices that combine superconducting and spintronic functions show promise forthe development of a nanoscale, nonvolatile, cryogenic memory technology.
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