The limit to realize an isolated magnetic single skyrmionic state

Abstract

The physical properties of a nanoparticle change drastically when the particle size approaches the length scale of the relevant order parameter. Herein, we demonstrate the ferrimagnetic ground state of Cu₂OSeO₃ nanoparticles, which is otherwise a chiral magnet (including large-size skyrmionic spin texture) in its bulk form. Theoretical studies suggest that such a pure ferrimagnetic ground state in this material (with low Dzyaloshinskii–Moriya interaction to Heisenberg interaction ratio) is possible only in the presence of magneto-crystalline anisotropy energy when the confinement size approaches the skyrmion size (∼50 nm in bulk). These observations suggest the limit to realize an isolated single skyrmion.