Noncollinear Antiferromagnets for Memory Applications and Beyond

Abstract

Noncollinear antiferromagnets (nc-AFMs) have gained attention for their potential use as spin-polarizing layer in novel magnetoresistive random access memory (MRAM) devices, due to the magnetic spin Hall effect (MSHE). Furthermore, strained nc-AFMs show a small but nonzero net-magnetization, that can be switched by spin-polarized current, making them suitable as magnetic memory layers as well. This work explores the switching dynamics of the nc-AFM Mn3Sn. We demonstrate, that deterministic switching in an Pt/Mn3Sn bilayer is achieved by controlling an applied charge current and external magnetic field. Furthermore, we explore possible mechanisms for fully electric mutual magnetization reversal in an Mn3Sn/Mo/CoFeB trilayer. We identify spin-orbit precession (SOP) at the Mo/CoFeB interface as well as the MSHE in the bulk of Mn3Sn as possible driving mechanisms. We demonstrate that through mutual switching in the trilayer-device, the polarization direction of MSHE-generated spin current can be electrically controlled.