Artificial "spin ice" in a geometrically frustrated lattice of nanoscale ferromagnetic islands

TL;DR

This paper presents an artificial two-dimensional spin ice system made of nanoscale ferromagnetic islands, enabling direct visualization and study of magnetic frustration phenomena similar to natural spin ice.

Contribution

It introduces a lithographically fabricated artificial spin ice lattice that mimics natural spin ice behavior, allowing direct imaging of frustration effects.

Findings

Observation of ice-like short-range magnetic correlations

Absence of long-range magnetic order

Behavior analogous to low-temperature spin ice states

Abstract

We report an artificial geometrically frustrated magnet based on an array of lithographically fabricated single-domain ferromagnetic islands. The islands are arranged such that the dipole interactions create a two-dimensional analogue to spin ice. Images of the magnetic moments of individual elements in this correlated system allow us to study the local accommodation of frustration. We see both ice-like short-range correlations and an absence of long-range correlations, behaviour which is strikingly similar to the lowtemperature state of spin ice. These results demonstrate that artificial frustrated magnets can provide an uncharted arena in which the physics of frustration can be directly visualized.