Creating an Artificial Two-Dimensional Skyrmion Crystal by Nanopatterning

TLDR

Skyrmion crystals arise from helical spin structures driven by the Dzyaloshinskii‑Moriya interaction, yet their study is limited by rarity and narrow temperature‑magnetic‑field stability ranges. The authors aim to assemble a two‑dimensional Skyrmion crystal using a perpendicularly magnetized film and nanopatterned arrays of confined magnetic vortices. Micromagnetic simulations and Skyrmion‑number calculations confirm the method’s feasibility. The scheme stabilizes Skyrmion crystals over a broad temperature and field range without intrinsic Dzyaloshinskii‑Moriya interactions, representing a qualitative breakthrough and significant quantitative improvement.

Abstract

A Skyrmion crystal typically arises from helical spin structures induced by the Dzyaloshinskii-Moriya interaction. Experimentally its physical exploration has been impeded because it is a rarity and is found only within a narrow temperature and magnetic field range. We present a method for the assembly of a two-dimensional Skyrmion crystal based upon a combination of a perpendicularly magnetized film and nanopatterned arrays of magnetic vortices that are geometrically confined within nanodisks. The practical feasibility of the method is validated by micromagnetic simulations and computed Skyrmion number per unit cell. We also quantify a wide range in temperature and field strength over which the Skyrmion crystal can be stabilized without the need for any intrinsic Dzyaloshinskii-Moriya interactions, which otherwise is needed to underpin the arrangement as is the case in the very few known Skyrmion crystal cases. Thus, our suggested scheme involves a qualitative breakthrough that comes with a substantial quantitative advance.