Simple strong glass forming models: mean-field solution with activation

TL;DR

This paper presents simple mean-field models for strong glass formers that incorporate activation processes, providing analytical solutions for their out-of-equilibrium dynamics at low temperatures.

Contribution

It introduces a generalized urn model with energy barriers and solves its out-of-equilibrium dynamics analytically in the mean-field approximation.

Findings

Models exhibit glassy dynamics with activated processes.

Analytical solutions describe aging behavior at low temperatures.

Models capture key features of strong glass formers.

Abstract

We introduce simple models, inspired by previous models for froths and covalent glasses, with trivial equilibrium properties but dynamical behaviour characteristic of strong glass forming systems. These models are also a generalization of backgammon or urn models to a non--constant number of particles, where entropic barriers are replaced by energy barriers, allowing for the existence of activated processes. We formulate a mean--field version of the models, which keeps most of the features of the finite dimensional ones, and solve analytically the out--of--equilibrium dynamics in the low temperature regime where activation plays an essential role.