Phase Transitions of Chiral Spin Textures via Dipolar Coupling in Multilayered Films with Interfacial DMI

TL;DR

This study explores how dipolar interactions influence the phase transitions of chiral spin textures, such as skyrmions and labyrinth domains, in multilayer films with interfacial DMI, providing insights for spintronic applications.

Contribution

It experimentally demonstrates the effect of interlayer dipolar coupling on spin texture phases and estimates the DMI energy in multilayer films, revealing new phase behaviors.

Findings

Dipolar energy modulates phase transitions of spin textures.

Skyrmion bubbles and labyrinth domains depend on DMI and dipolar energy.

Estimated DMI energy in multilayers is approximately 2.1 mJ/m².

Abstract

Under the correct conditions, Dzyaloshinskii-Moriya interactions (DMI) can lead to topologically protected spin textures such as skyrmions. The application of DMI for spin-based computation and memory technologies is promising and requires a detailed consideration of the role intrinsic energies have on stabilizing the diverse textures observed thus far. Here we experimentally investigate the effect of dipolar energy from interlayer coupling on the remanent spin textures found at room temperature for interfacial DMI multilayers of [ Pt \ Co \ Ir ]$_{\times N}$. The total dipolar energy is modified by increasing the number of layer repetitions N which result in different phases of chiral magnetic textures. We use the phase transitions to estimate the DMI energy present in the ultrathin films to be D = 2.1 $\pm$ 0.1 mJ m$^{-2}$. Unlike traditional perpendicular magnetic anisotropy films, these multilayer films with finite DMI exhibit isolated hedgehog skyrmion bubbles as well as sub 100 nm labyrinth domains with cycloidal homochiral N\'eel walls which are dependent on DMI as well as the total dipolar energy.