Connected Network of Minima as a Model Glass: Long Time Dynamics

TL;DR

This paper introduces a simple model representing glass-formers as a connected network of minima, capturing long-time dynamics and explaining phenomena like stretched relaxation and Stokes-Einstein law breakdown.

Contribution

The model provides a new framework to understand glassy dynamics by representing the system as harmonic vibrations and jumps within a connected minima network.

Findings

Evidence for stretched relaxational dynamics

Strong temperature dependence of relaxation properties

Breakdown of the Stokes-Einstein law in the model

Abstract

A simple model to investigate the long time dynamics of glass-formers is presented and applied to study a Lennard-Jones system in supercooled and glassy phases. According to our model, the point representing the system in the configurational phase space performs harmonic vibrations around (and activated jumps between) minima pertaining to a connected network. Exploiting the model, in agreement with the experimental results, we find evidence for: i) stretched relaxational dynamics; ii) a strong T-dependence of the stretching parameter; iii) breakdown of the Stokes-Einstein law.