Field-Dependent Size and Shape of Single Magnetic Skyrmions

TLDR

Spin‑polarized STM was used to image the atomic‑scale spin structure of isolated skyrmions, and an analytical expression was introduced to link the measurements to the chiral skyrmion model. The skyrmions exhibit axial symmetry and a distinct rotational sense, with their size and shape varying with magnetic field, allowing extraction of the material parameters governing skyrmion formation.

Abstract

The atomic-scale spin structure of individual isolated Skyrmions in an ultrathin film is investigated in real space by spin-polarized scanning tunneling microscopy. Their axial symmetry as well as their unique rotational sense is revealed by using both out-of-plane and in-plane sensitive tips. The size and shape of Skyrmions change as a function of the magnetic field. An analytical expression for the description of Skyrmions is proposed and applied to connect the experimental data to the original theoretical model describing chiral Skyrmions. Thereby, the relevant material parameters responsible for Skyrmion formation can be obtained.