Growth-Dependent Interlayer Chiral Exchange and Field-Free Switching

Abstract

The interfacial Dzyaloshinskii-Moriya interaction (DMI) has long been observed in normal metal/ferromagnetic multilayers, enabling the formation of chiral domain walls, skyrmions, and other two-dimensional antisymmetric spin textures confined within a single ferromagnetic layer, while more recent works on the interlayer DMI reveal alternative pathways for realizing chiral three-dimensional spin textures by extending the DMI to two spatially distinct magnetic layers. Here, we report on the interlayer DMI between two orthogonally magnetized ferromagnetic layers ($\mathrm{Co}\text{\ensuremath{-}}\mathrm{Fe}\text{\ensuremath{-}}\mathrm{B}/\mathrm{Co}$) mediated by a $\mathrm{Pt}$ layer and confirm the chiral nature of the observed effective field of up to 37 Oe through asymmetric hysteresis loops under an 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 $\mathrm{Co}$ layer utilizing solely the effective field from the interlayer DMI. These results demonstrate the interlayer DMI's potential to facilitate deterministic field-free switching in spin-memory applications.