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

TL;DR

This paper demonstrates reliable sub-nanosecond electrical switching of antiferromagnetic insulators using pulses as short as 0.3 ns, highlighting thermally-assisted spin-orbit torque effects.

Contribution

It provides the first experimental evidence of sub-ns electrical switching in AFM insulators, expanding the potential for ultrafast AFM spintronics.

Findings

Achieved AFM switching with pulses down to 0.3 ns.

Thermally-assisted spin-orbit torque likely facilitates ultrafast switching.

Simulations support temperature's role in switching mechanism.

Abstract

Electrical switching of antiferromagnets (AFM) is critical for AFM spintronics. However, electrical pulse-induced Neel vector reorientation in AFM insulators, while predicted to occur at much faster timescales than ferromagnetic switching, has only been demonstrated in the quasi-DC regime. Here we report reliable current-induced AFM switching in Pt/$\alpha$-Fe$_2$O$_3$ bilayers using electrical pulses with various durations spanning three orders of magnitude down to 0.3 ns. Together with COMSOL simulations of temperature distributions in our samples for various pulse widths, our results suggest that thermally-assisted spin-orbit torque likely play an important role for sub-ns pulses. This work demonstrates the viability of electrical switching of AFM spins using sub-ns pulses.