Releasing latent chirality in magnetic two-dimensional materials

TL;DR

This paper reveals that intrinsic Dzyaloshinskii-Moriya interaction (DMI) exists in 2D magnetic materials like CrI3 and can be activated by structural asymmetries, enabling new control methods for chiral magnetism in 2D systems.

Contribution

It demonstrates the presence of latent DMI in 2D magnetic materials and how it can be released and controlled through structural and external electric field modifications.

Findings

Intrinsic DMI exists in 2D magnetic materials.

Structural asymmetries activate the latent DMI.

External electric fields can tune the DMI.

Abstract

Dzyaloshinskii-Moriya interaction is at heart of chiral magnetism and causes emergence of rich non-collinear and unique topological spin textures in magnetic materials, including cycloids, helices, skyrmions and other. Here we show that strong intrinsic DMI lives in recently discovered van der Waals magnetic two-dimensional materials, due to the sizeable spin-orbit coupling on the non-magnetic ions. In a perfect crystal, this intrinsic DMI remains hidden, but is released with any break of point-inversion symmetry between magnetic ions, unavoidable at the sample edges, at ever present structural defects, with any buckling of the material, or with non-uniform strain on an uneven substrate. We demonstrate such release of latent chirality on an archetypal magnetic monolayer - CrI3, and discuss the plethora of realizable DMI patterns, their control by nanoengineering and tuning by external electric field, thereby opening novel routes in 2D magnetoelectronics.