Effective Temperature in an Interacting, Externally Driven, Vertex System: Theory and Experiment on Artificial Spin Ice

TL;DR

This paper demonstrates that the statistical behavior of artificial spin ice systems, despite being athermal, can be effectively described using a temperature derived from magnetostatic energy, linking external driving to system configurations.

Contribution

It introduces an effective temperature concept for driven, interacting nanomagnet arrays, bridging athermal systems with thermodynamic descriptions.

Findings

Effective temperature accurately predicts moment configurations.

The temperature relates to external oscillating magnetic fields.

Applicable to both hexagonal and square lattice spin ice.

Abstract

Frustrated arrays of interacting single-domain nanomagnets provide important model systems for statistical mechanics, because they map closely onto well-studied vertex models and are amenable to direct imaging and custom engineering. Although these systems are manifestly athermal, we demonstrate that the statistical properties of both hexagonal and square lattices can be described by an effective temperature based on the magnetostatic energy of the arrays. This temperature has predictive power for the moment configurations and is intimately related to how the moments are driven by an oscillating external field.