Continuous local model for two-dimensional spin ice

TL;DR

This paper introduces a classical 2D spin ice model Hamiltonian that exhibits magnetic monopole excitations and reveals how local interactions can produce effective nonlocal monopole-dipole interactions.

Contribution

It presents a novel local classical spin model that captures monopole excitations and their interactions in two-dimensional spin ice.

Findings

Emergence of magnetic monopoles as metastable excitations

Effective nonlocal interactions derived from local spin interactions

Analysis of monopole-dipole interactions in the model

Abstract

We propose a classical model Hamiltonian with a ground state presenting a spin ice structure. We analyze the introduction of metastable excitations on this ground state, showing the emergence of pairs of magnetic monopoles. The interaction between monopoles and dipoles in the system is studied. As a consequence, we obtain an effective nonlocal interaction between monopoles and dipoles from a local classical spin model.