The combination of superconducting and magnetic materials to create novel superconducting devices has been motivated by the discovery of Josephson critical current (Ics) oscillations as a function of magnetic layer thickness and the demonstration of devices with switchable critical currents. However, none of the hybrid devices have shown any spintronic effects, such as spin-transfer torque, which are currently used in room-temperature magnetic devices, including spin-transfer torque random-access memory and spin-torque nano-oscillators. We have developed nanopillar Josephson junctions with a minimum feature size of 50 nm and magnetic barriers exhibiting magnetic pseudo-spin-valve behavior at 4 K. These devices allow current-induced magnetization switching that results in 20-fold changes in Ics. The current-induced magnetic switching is consistent with spin-transfer torque models for room-temperature magnetic devices. Our work demonstrates that devices that combine superconducting and spintronic functions show promise for the development of a nanoscale, nonvolatile, cryogenic memory technology.
@article{arxiv.1410.4529,
title = {Spin-transfer torque switching in nanopillar superconducting-magnetic hybrid Josephson junctions},
author = {Burm Baek and William H. Rippard and Matthew R. Pufall and Samuel P. Benz and Stephen E. Russek and Horst Rogalla and Paul D. Dresselhaus},
journal= {arXiv preprint arXiv:1410.4529},
year = {2015}
}