Current-driven thermo-magnetic switching in magnetic tunnel junctions

TL;DR

This paper explores a novel current-driven thermal switching mechanism in magnetic tunnel junctions, utilizing a composite free layer that undergoes a Curie transition to enable efficient magnetic reversal near room temperature.

Contribution

It introduces a thermally induced switching method in MTJs using a composite free layer with a Curie transition, offering tunability and potential advantages over spin-transfer torque techniques.

Findings

Heat focusing improves power efficiency.

Switching occurs via a Curie transition in the free layer.

Device operates effectively near room temperature.

Abstract

We investigate switching of magnetic tunnel junctions (MTJs) driven by the thermal effect of the transport current through the junctions. The switching occurs in a specially designed composite free layer, which acts as one of the MTJ electrodes, and is due to a current-driven ferro-to-paramagnetic Curie transition with the associated exchange decoupling within the free layer leading to magnetic reversal. We simulate the current and heat propagation through the device and show how heat focusing can be used to improve the power efficiency. The Curie-switch MTJ demonstrated in this work has the advantage of being highly tunable in terms of its operating temperature range, conveniently to or just above room temperature, which can be of technological significance and competitive with the known switching methods using spin-transfer torques.