Single-shot laser-induced switching of an exchange biased antiferromagnet

TL;DR

This paper demonstrates ultrafast, single-shot switching of antiferromagnetic order in IrMn/CoGd bilayers using femtosecond laser pulses, advancing the control of magnetic states for spintronic applications.

Contribution

It introduces the first demonstration of single-shot laser-induced switching of an antiferromagnet's exchange bias, with atomistic simulations supporting ultrafast dynamics.

Findings

Switching of exchange bias sign achieved with femtosecond laser pulses.

Switching occurs across various fluences, layer thicknesses, and compositions.

Simulations predict AFM magnetization recovery within 2 ps.

Abstract

Ultrafast manipulation of magnetic order has challenged our understanding the fundamental and dynamic properties of magnetic materials. So far single shot magnetic switching has been limited to ferrimagnetic alloys and multilayers. In ferromagnetic (FM)/antiferromagnetic (AFM) bilayers, exchange bias (He) arises from the interfacial exchange coupling between the two layers and reflects the microscopic orientation of the antiferromagnet. Here we demonstrate the possibility of single shot switching of the antiferromagnet (change of the sign and amplitude of He) with a single femtosecond laser pulse in IrMn/CoGd bilayers. We demonstrate the switching for a wide range of fluences for different layer thicknesses and compositions. Atomistic simulations predict ultrafast switching and recovery of the AFM magnetization on a timescale of 2 ps. These results provide the fastest and the most energy-efficient method to set the exchange bias and pave the way to potential applications for ultrafast spintronic devices.