Tuning interfacial spins in antiferromagnetic / ferromagnetic / heavy metal heterostructures via spin-orbit torque

TL;DR

This paper demonstrates precise control of interfacial spins in antiferromagnetic/ferromagnetic/heavy metal heterostructures using spin-orbit torque, enabling multiple spin states and field-free switching for advanced spintronic devices.

Contribution

It introduces a method to manipulate interfacial antiferromagnetic spins via spin-orbit torque with multiple states and field-free switching, advancing spintronic device design.

Findings

Multiple intermediate spin states achieved

Field-free spin switching observed

Interfacial spin control demonstrated

Abstract

Antiferromagnets are outstanding candidates for the next generation of spintronic applications, with great potential for downscaling and decreasing power consumption. Recently, the manipulation of bulk properties of antiferromagnets has been realized by several different approaches. However, the interfacial spin order of antiferromagnets is an important integral part of spintronic devices, thus the successful control of interfacial antiferromagnetic spins is urgently desired. Here, we report the high controllability of interfacial spins in antiferromagnetic / ferromagnetic / heavy metal heterostructure devices using spin-orbit torque (SOT) assisted by perpendicular or longitudinal magnetic fields. Switching of the interfacial spins from one to another direction through multiple intermediate states is demonstrated. The field-free SOT-induced switching of antiferromagnetic interfacial spins is also observed, which we attribute to the effective built-in out-of-plane field due to unequal upward and downward interfacial spin populations. Our work provides a precise way to modulate the interfacial spins at an antiferromagnet / ferromagnet interface via SOT, which will greatly promote innovative designs for next generation spintronic devices.