Sub-Nanosecond Electrical Pulse Switching of an Easy Plane Antiferromagnetic Insulator

Antiferromagnetic insulators (AFIs) are a promising candidate for new high speed magnetic memory materials. If the current-induced Néel order switching that has been previously observed in heavy-metal/AFI bilayers is due to spin orbit torques, this promises the ability to manipulate these materials at a much higher frequency than is currently allowed by intrinsic limits in ferromagnet-based memory. However, there is still considerable debate about the mechanism of the observed switching, as previous reports show a significant contribution from the relatively slow thermally-induced magnetoelastic effect in the quasi-dc pulse width regime. Here we report reliable current-induced switching of the easy plane antiferromagnet Hematite (α-Fe₂O₃) with a Platinum overlayer down to 300 ps. We examine the switching threshold dependence as a function of electrical pulse width, which strongly indicates that in this regime spin orbit torques are the dominant mechanism, reaffirming antiferromagnetic spintronic devices as a promising new system for high-frequency applications.