Electrically Switchable Ferromagnetic Josephson Junctions

This experimental project in superconducting spintronics will study spin-torques in ferromagnetic superconducting Josephson Junctions. Superconducting computers operating at 4.2K have been proposed to solve the problems of energy usage by large-scale computing, as components for a neuromorphic computer and to interface between a quantum computer operator at millikelvin temperatures and conventional room temperature electronics. Whilst the technology to implement logic in such a 4.2K computer is well established, there remains, a yet, no suitable technology to implement cryogenic memory beyond registers. This project aims to address this need by developing the physics and materials to implement memory technologies based on ferromagnetic Josephson junctions.

A ferromagnetic Josephson junction based memory combines the magnetic storage capabilities of a conventional magneto-resistive RAM cell with the dissipation- less nature of superconductors. As with the first generation of MRAM designs, our initial ferromagnetic Josephson junction designs rely on an applied field to set the state of the junction 1-3. In a modern MRAM cell, the state is set by making use of spin-transfer torque or spin-orbit torques to electrical change the magnetic state. To date, there has not been the equivalent step taken with the superconducting junction counterparts.