Disorder strength and field-driven ground state domain formation in artificial spin ice: experiment, simulation and theory

TL;DR

This study investigates how quenched disorder influences domain formation and edge effects in artificial spin ice, combining experiments, simulations, and theory to understand non-equilibrium responses to external fields.

Contribution

It provides experimental, numerical, and analytical insights into the role of disorder in artificial spin ice, especially regarding ground state access and edge effect suppression.

Findings

Disorder washes out edge effects in artificial spin ice.

A fixed-amplitude field sequence cannot reach the ground state from saturation.

Estimated disorder strength in the experimental system.

Abstract

Quenched disorder affects how non-equilibrium systems respond to driving. In the context of artificial spin ice, an athermal system comprised of geometrically frustrated classical Ising spins with a two-fold degenerate ground state, we give experimental and numerical evidence of how such disorder washes out edge effects, and provide an estimate of disorder strength in the experimental system. We prove analytically that a sequence of applied fields with fixed amplitude is unable to drive the system to its ground state from a saturated state. These results should be relevant for other systems where disorder does not change the nature of the ground state.