Magnetic Nanohorns for measurement of the interfacial Dzyaloshinskii-Moriya interaction: A micromagnetic study

TL;DR

This study proposes a micromagnetic method using nanohorn-shaped structures to measure the interfacial Dzyaloshinskii-Moriya interaction by analyzing the equilibrium position of domain walls under magnetic fields.

Contribution

It introduces a novel approach combining numerical and semi-analytical calculations to quantify DMI strength via nanohorn geometries, facilitating easier experimental measurement.

Findings

DMI strength correlates with domain wall equilibrium position.

Tapering degree controls the measurable DMI range.

Numerical and semi-analytical results show broad agreement.

Abstract

We evaluate the micromagnetic energy of a domain wall contained in a thin, horn-shaped nanostructure and propose a method to extract the strength of the interfacial Dzyaloshinskii-Moriya interaction based on the equilibrium position of the wall. An inplane magnetic field coupled with the interfacial DMI balances a competing driving force related to the "nanohorn" tapering and consequent variation in length. It is evident that the strength of the the DMI is directly correlated to the equilibrium position of the DW. Moreover, the range of measurable DMI values can be controlled by varying the degree of tapering in the nanohorn. Numerical and semi-analytical calculations were separately performed and show broad agreement. The calculations provided here offer an alternative framework for future measurement of DMI, which has been notoriously difficult to do experimentally.