Vortex ground state for small arrays of magnetic particles with dipole coupling

TL;DR

This paper demonstrates that small arrays of magnetic particles arranged in a hexagonal triangular lattice can naturally form vortex ground states, with their stability influenced by magnetic anisotropy, even at nanoscale sizes.

Contribution

It reveals the existence and stability conditions of vortex ground states in small magnetic particle arrays with dipole coupling, expanding understanding of nanoscale magnetic configurations.

Findings

Vortex ground states exist in arrays with N ≤ 100 particles.

Increasing magnetic anisotropy affects vortex core appearance and stability.

Vortices can form in arrays as small as a few dozen nanometers.

Abstract

We show that a magnetic vortex is the ground state of an array of magnetic particles shaped as a hexagonal fragment of a triangular lattice, even for an small number of particles in the array $N \leq 100$. The vortex core appears and the symmetry of the vortex state changes with the increase of the intrinsic magnetic anisotropy of the particle $\beta$; the further increase of $\beta$ leads to the destruction of the vortex state. Such vortices can be present in arrays as small in size as dozen of nanometers.