Readout of a antiferromagnetic spintronics systems by strong exchange coupling of Mn2Au and Permalloy

TL;DR

This paper demonstrates strong exchange coupling between Mn2Au antiferromagnetic and Permalloy ferromagnetic layers, enabling effective read-out of antiferromagnetic states using ferromagnetic techniques, which advances antiferromagnetic spintronics applications.

Contribution

It introduces a method to read out antiferromagnetic states via ferromagnetic layers through strong exchange coupling, utilizing high-quality interfaces for improved spintronic device functionality.

Findings

Strong exchange coupling between Mn2Au and Permalloy layers.

Imprinting of antiferromagnetic domain patterns onto ferromagnets.

Reorientation of Mn2Au Neel vector via Permalloy magnetization.

Abstract

In antiferromagnetic spintronics, the read-out of the staggered magnetization or Neel vector is the key obstacle to harnessing the ultra-fast dynamics and stability of antiferromagnets for novel devices. Here, we demonstrate strong exchange coupling of Mn2Au, a unique metallic antiferromagnet that exhibits Neel spin-orbit torques, with thin ferromagnetic Permalloy layers. This allows us to benefit from the well-estabished read-out methods of ferromagnets, while the essential advantages of antiferromagnetic spintronics are retained. We show one-to-one imprinting of the antiferromagnetic on the ferromagnetic domain pattern. Conversely, alignment of the Permalloy magnetization reorients the Mn2Au Neel vector, an effect, which can be restricted to large magnetic fields by tuning the ferromagnetic layer thickness. To understand the origin of the strong coupling, we carry out high resolution electron microscopy imaging and we find that our growth yields an interface with a well-defined morphology that leads to the strong exchange coupling.