Thermal contribution to current-driven antiferromagnetic-order switching

Abstract

In information technology devices, current-driven state switching is crucial in various disciplines including spintronics, where the contribution of heating to the switching mechanism plays an inevitable role. Recently, current-driven antiferromagnetic order switching has attracted considerable attention due to its implications for next-generation spintronic devices. Although the switching mechanisms can be explained by spin dynamics induced by spin torques, some reports have claimed that demagnetization above the Néel temperature due to Joule heating is critical for switching. Here, we present a systematic method and an analytical model to quantify the thermal contribution due to Joule heating in micro-electronic devices, focusing on current-driven octupole switching in the non-collinear antiferromagnet, Mn3Sn. The results consistently show that the critical temperature for switching remains relatively constant above the Néel temperature, while the threshold current density depends on the choice of substrate and the base temperature. In addition, we provide an analytical model to calculate the Joule-heating temperature, which quantitatively explains our experimental results. From numerical calculations, we illustrate the reconfiguration of magnetic order during cooling from a demagnetized state of polycrystalline Mn3Sn. This work provides not only deeper insights into magnetization switching in antiferromagnets, but also a general guideline for evaluating the Joule-heating temperature excursions in micro-electronic devices.