Fractal Analysis of Skyrmions Generated by Field-Assisted Fine-tuning of Magnetic Anisotropy

Yao Zhang, Guy Dubuis, Tane Butler, and Simon Granville
Phys. Rev. Applied 15, 014020 – Published 12 January 2021
PDFHTMLExport Citation

Abstract

Magnetic skyrmions are topologically protected whirling spin textures nucleated from other ferromagnetic states that have great potential applications for nanoscale devices. To realize this potential, it is important to find useful methods to generate skyrmions in a controlled fashion and to identify tools to quantitatively describe their formation. Here we generate skyrmions in perpendicularly magnetized MgO/Mn2CoAl/Pd ultrathin films and investigate their formation by fractal analysis. Using an in-plane field, we modify the effective magnetic anisotropy of the films to control the nucleation of skyrmions from two distinct domain states in the films: labyrinth domains typically found in perpendicular materials and a featureless monodomain ferromagnetic phase. By using fractal analysis, we obtain a magnetic phase diagram related to the fractal dimension of the domains that can describe the evolution of the magnetic states and can be used to categorize the formation of skyrmions. Moreover, we find that the skyrmion density is determined not only by the critical material parameter κ but also by a repulsive skyrmion-skyrmion interaction at high in-plane magnetic fields. We thus establish a reliable and powerful method to generate skyrmions and a way to analyze the evolution of skyrmions.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 20 September 2020
  • Revised 19 November 2020
  • Accepted 9 December 2020

DOI:https://doi.org/10.1103/PhysRevApplied.15.014020

© 2021 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Yao Zhang1,2,3, Guy Dubuis1,2,*, Tane Butler1,2,3, and Simon Granville1,2,†

  • 1Robinson Research Institute, Victoria University of Wellington, Wellington, New Zealand
  • 2MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
  • 3School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand

  • *guy.dubuis@vuw.ac.nz
  • simon.granville@vuw.ac.nz

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 15, Iss. 1 — January 2021

Subject Areas
Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Applied

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×