Non-volatile electric control of spin-orbit torques in an oxide two-dimensional electron gas

TL;DR

This paper demonstrates non-volatile electric control of spin-orbit torques in an oxide-based 2DEG, enabling reversible and stable manipulation of magnetic states for advanced spintronic devices.

Contribution

It introduces a method to electrically control SOTs in oxide 2DEGs with remanent states, enhancing reconfigurability in spintronic applications.

Findings

Achieved non-volatile control of SOTs using back-gate electric fields.

Demonstrated two remanent, switchable states with large resistance contrast.

Validated compatibility with magnetic tunnel junctions for reconfigurable devices.

Abstract

Spin-orbit torques (SOTs) have opened a novel way to manipulate the magnetization using in-plane current, with a great potential for the development of fast and low power information technologies. It has been recently shown that two-dimensional electron gases (2DEGs) appearing at oxide interfaces provide a highly efficient spin-to-charge current interconversion. The ability to manipulate 2DEGs using gate voltages could offer a degree of freedom lacking in the classical ferromagnetic/spin Hall effect bilayers for spin-orbitronics, in which the sign and amplitude of SOTs at a given current are fixed by the stack structure. Here, we report the non-volatile electric-field control of SOTs in an oxide-based Rashba-Edelstein 2DEG. We demonstrate that the 2DEG is controlled using a back-gate electric-field, providing two remanent and switchable states, with a large resistance contrast of 1064%. The SOTs can then be controlled electrically in a non-volatile way, both in amplitude and in sign. This achievement in a 2DEG-CoFeB/MgO heterostructures with large perpendicular magnetization further validates the compatibility of oxide 2DEGs for magnetic tunnel junction integration, paving the way to the advent of electrically reconfigurable SOT MRAMS circuits, SOT oscillators, skyrmion and domain-wall-based devices, and magnonic circuits.