Magnetostatic twists in room-temperature skyrmions explored by nitrogen-vacancy center spin texture reconstruction

TLDR

Magnetic skyrmions are two‑dimensional non‑collinear spin textures with an integer topological number, and room‑temperature skyrmions have recently been found in magnetic multilayer stacks where their stability is largely attributed to interfacial Dzyaloshinskii–Moriya interaction. The study aims to determine the strength of the interfacial Dzyaloshinskii–Moriya interaction and its role in stabilizing skyrmions by imaging the full spin structure. Using a nitrogen‑vacancy centre in diamond, the authors map the magnetic fields produced by a skyrmion in a multilayer at ambient conditions and compute a manifold of candidate spin structures to select the physically meaningful solution. They discover a Néel‑type skyrmion with non‑left‑handed chirality, propose tube‑like structures whose chirality rotates through the film thickness, and demonstrate that NV magnetometry with their analysis method uniquely probes this previously inaccessible phenomenon.

Abstract

Abstract Magnetic skyrmions are two-dimensional non-collinear spin textures characterized by an integer topological number. Room-temperature skyrmions were recently found in magnetic multilayer stacks, where their stability was largely attributed to the interfacial Dzyaloshinskii–Moriya interaction. The strength of this interaction and its role in stabilizing the skyrmions is not yet well understood, and imaging of the full spin structure is needed to address this question. Here, we use a nitrogen-vacancy centre in diamond to measure a map of magnetic fields produced by a skyrmion in a magnetic multilayer under ambient conditions. We compute the manifold of candidate spin structures and select the physically meaningful solution. We find a Néel-type skyrmion whose chirality is not left-handed, contrary to preceding reports. We propose skyrmion tube-like structures whose chirality rotates through the film thickness. We show that NV magnetometry, combined with our analysis method, provides a unique tool to investigate this previously inaccessible phenomenon.