Growth-dependent Interlayer Chiral Exchange and Field-free Switching

TL;DR

This paper demonstrates growth-induced interlayer Dzyaloshinskii-Moriya interaction (DMI) between orthogonally magnetized layers, enabling deterministic, field-free magnetization switching crucial for spin memory technologies.

Contribution

It reveals a novel interlayer DMI mediated by a Pt layer between orthogonal ferromagnetic layers, with growth-induced symmetry breaking enabling field-free switching.

Findings

Interlayer DMI observed with effective field up to 37 Oe.

Growth-induced in-plane symmetry breaking is crucial.

Deterministic current-driven switching achieved without external fields.

Abstract

Interfacial Dzyaloshinskii-Moriya interaction (DMI) has long been observed in normal metal/ferromagnetic multilayers, enabling the formation of chiral domain walls, skyrmions and other 2D antisymmetric spin textures confined within a single ferromagnetic layer, while more recent works on interlayer DMI reveal new pathways in realizing novel chiral 3D spin textures between two separate layers.Here, we report on interlayer DMI between two orthogonally magnetized ferromagnetic layers (CoFeB/Co) mediated by a Pt layer, and confirm the chiral nature of the observed effective field of up to 37 Oe through asymmetric hysteresis loops under in-plane field.We highlight the importance of growth-induced in-plane symmetry breaking, resulting in a sizable interlayer DMI and a universal characteristic vector through wedge deposition of the samples.We further perform deterministic current-driven magnetization switching in the perpendicularly magnetized Co layer utilizing solely the effective field from the interlayer DMI.These results demonstrate the potential of interlayer DMI in facilitating deterministic field-free switching in spin memory applications.