Spin-transfer torque switching observed in nanopillar superconducting-magnetic hybrid Josephson junctions

Published: January 09, 2015


Burm Baek, William H. Rippard, Matthew R. Pufall, Samuel P. Benz, Stephen E. Russek, Horst Rogalla, Paul D. Dresselhaus


Combining superconducting and magnetic materials to create novel superconducting devices has been motivated by the discovery of the Josephson critical current (Ics) oscillations with 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, that are presently being used in room-temperature magnetic devices, such as spin- transfer torque random access memory and spin torque nano-oscillators. We have developed nanopillar Josephson junctions with a minimum feature size down to 50 nm and barriers exhibiting magnetic pseudo-spin-valve behavior at 4 K. These devices allow current-induced magnetization switching that results in changes in Ics up to 2000 %. The observed current- induced magnetic switching is consistent with the spin-transfer torque models for room- temperature magnetic devices. Our work demonstrates that devices combining superconducting and spintronic functions show promise for the development of a nanoscale, nonvolatile, cryogenic memory technology.
Citation: Nature Materials
Volume: 3
Issue: 1
Pub Type: Journals


Josephson junction, spin valve, cryogenic memory, superconducting electronics, spintronics
Created January 09, 2015, Updated November 10, 2018