Magnetoelectric effect in dipolar clusters

TL;DR

This paper investigates dipolar clusters with specific symmetry properties, revealing their ability to generate spin currents and exhibit the magnetoelectric effect, which could inform the design of room-temperature magnetoelectric devices.

Contribution

It introduces a novel theoretical framework linking dipolar cluster symmetry to magnetoelectric effects, advancing the understanding of multiferroic metamaterials.

Findings

Clusters carry spin current

Manifest magnetoelectric effect

Symmetry groups match crystal field models

Abstract

We combine the anisotropy of magnetic interactions and the point symmetry of finite solids in the study of dipolar clusters as new basic units for multiferroics metamaterials. The hamiltonian of magnetic dipoles with an easy axis at the vertices of polygons and polyhedra, maps exactly into a hamiltonian with symmetric and antisymmetric exchange couplings. The last one gives rise to a Dzyaloshinskii-Moriya contribution responsible for the magnetic modes of the systems and their symmetry groups, which coincide with those of a particle in a crystal field with spin-orbit interaction. We find that the clusters carry spin current and that they manifest the magnetoelectric effect. We expect our results to pave the way for the rational design of magnetoelectric devices at room temperature.