Controlled topological dilution drives cooperative glassy dynamics in artificial spin ice

TL;DR

This study demonstrates that controlled disorder via random decimation in artificial spin ice induces glassy magnetic dynamics, including aging and dynamical heterogeneity, transitioning from ordered to glass-like states.

Contribution

It introduces a method to systematically control disorder in artificial spin ice, revealing its role in driving glassy behavior and complex dynamics.

Findings

Decimation increases higher energy vertices and configurational entropy.

Higher decimation leads to slow cooperative dynamics and aging.

Transition from thermally activated to Vogel-Fulcher freezing observed.

Abstract

It has long been known that disorder, perturbing the energy landscape of magnetic systems, can introduce glassy dynamics. However, the controlled role of increasing disorder in driving glass formation remains difficult to isolate in naturally occurring materials. Artificial spin ice offers a unique model platform in which geometry, interactions, and disorder can be engineered at the nanoscale. Here, we investigate the impact of controlled disorder introduced through random decimation in artificial square spin ice. By systematically removing nanomagnets from random sites, we modify the vertex topology and progressively increase frustration in the spin network. Synchrotron-based photoemission electron microscopy reveals that decimation enhances the population of higher energy vertices and increases the configurational entropy of the system. Time-resolved temperature-dependent imaging further shows the emergence of slow cooperative dynamics at higher decimation, characterized by aging, a finite Edwards--Anderson order parameter, and enhanced dynamical heterogeneity quantified by the four-point susceptibility. The relaxation dynamics transition from thermally activated behavior at low decimation to Vogel--Fulcher--type freezing at higher decimation. These results demonstrate that random decimation drives artificial spin ice from long-range order to a glass-like magnetic state, establishing artificial spin systems as a tunable platform for studying glassy dynamics in frustrated matter.