Aging in a simple model of a structural glass

TL;DR

This paper studies aging phenomena in a simple lattice gas model of a structural glass, showing how density approaches a critical point with aging behavior after a quench, explained via mean-field theory.

Contribution

It introduces a minimal lattice gas model with kinetic constraints to analyze aging in structural glasses, providing a mean-field explanation for observed dynamics.

Findings

Density approaches critical density following a power law in time

Two-time self-correlation functions exhibit aging behavior

Diffusion coefficient vanishes at the critical density

Abstract

We consider a simple model of a structural glass, represented by a lattice gas with kinetic constraints in contact with a particle reservoir. Quench below the glass transition is represented by the jump of the chemical potential above a threshold. After a quench, the density approaches the critical density-where the diffusion coefficient of the particles vanishes-following a power law in time. In this regime, the two-time self-correlation functions exhibit aging. The behavior of the model can be understood in terms of simple mean-field arguments.