Theory of vortex states in magnetic nanodisks with induced Dzyaloshinskii-Moriya interactions

TL;DR

This paper investigates how surface-induced Dzyaloshinskii-Moriya interactions influence vortex states in magnetic nanodisks, revealing their impact on vortex size, chirality, and potential for bistable storage applications.

Contribution

It provides a micromagnetic analysis of vortex size and shape dependence on Dzyaloshinskii-Moriya interactions in nanodisks, highlighting their role in stabilizing homochiral vortices.

Findings

Dzyaloshinskii-Moriya coupling increases vortex size with right chirality

It suppresses vortices with opposite chirality

Enables formation of bistable homochiral vortex systems

Abstract

Vortex states in magnetic nanodisks are essentially affected by surface/interface induced Dzyaloshinskii-Moriya interactions. Within a micromagnetic approach we calculate the equilibrium sizes and shape of the vortices as functions of magnetic field, the material and geometrical parameters of nanodisks. It was found that the Dzyaloshinskii-Moriya coupling can considerably increase sizes of vortices with "right" chirality and suppress vortices with opposite chirality. This allows to form a bistable system of homochiral vortices as a basic element for storage applications.