Determination of the Dzyaloshinskii-Moriya interactions

TL;DR

This paper introduces a method to determine bulk and interfacial Dzyaloshinskii-Moriya interactions by analyzing the in-plane field dependence of chiral domain wall motion, providing a new way to quantify these interactions in magnetic heterostructures.

Contribution

It proposes a novel approach to simultaneously measure bulk and interfacial DMIs using in-plane field dependence of domain wall dynamics, with procedures validated on experimental data.

Findings

Effective fields of DMIs have distinct transverse and longitudinal components.

Domain wall velocity exhibits dome- or canyon-shaped dependence on in-plane field.

Reversal of topological charge and current/field direction helps identify DMI characteristics.

Abstract

Using in-plane field dependence of the precessional flow of chiral domain walls (DWs) to simultaneously determine bulk and interfacial Dzyaloshinskii-Moriya interactions (DMIs) is proposed. It is found that effective fields of bulk and interfacial DMIs have respectively transverse and longitudinal components that affect differently the motion of chiral DWs in magnetic narrow heterostructure strips. The in-plane field dependence of DW velocity has a dome-shape or a canyon-shape, depending on whether the driving force is an in-plane current or an out-of-plane magnetic field. The responses of their center shifts to the reversal of topological wall charge and current/field direction uniquely determine the nature and strength of DMI therein. Operable procedures are proposed and applied to explain existing experimental data.