Real-space model for activated processes in rejuvenation and memory behavior of glassy systems

TL;DR

This paper introduces a real-space, activated-process-based model using a lattice cluster approach to explain rejuvenation and memory effects in glassy systems during aging, aligning with experimental observations.

Contribution

It presents a simplified cluster model that captures complex aging phenomena like rejuvenation and memory in glassy systems, offering an alternative to hierarchical landscape descriptions.

Findings

Model reproduces rejuvenation effects in glassy systems.

Model captures memory effects during aging.

Aligns with experimental observations of colloidal systems.

Abstract

We offer an alternative real-space description, based purely on activated processes, for the understanding of relaxation dynamics in hierarchical landscapes. To this end, we use the cluster model, a coarse-grained lattice model of a jammed system, to analyze rejuvenation and memory effects during aging after a hard quench. In this model, neighboring particles on a lattice aggregate through local interactions into clusters that fragment with a probability based on their size. Despite the simplicity of the cluster model, it has been shown to reproduce salient observables of the aging dynamics in colloidal systems, such as those accounting for particle mobility and displacements. Here, we probe the model for more complex quench protocols and show that it exhibits rejuvenation and memory effects similar to those attributed to the complex hierarchical structure of a glassy energy landscape.