Space-time Thermodynamics of the Glass Transition

TL;DR

This paper proposes a space-time thermodynamics perspective on the glass transition, viewing it as a phase coexistence in trajectory space driven by dynamic heterogeneity and low action fluctuations.

Contribution

It introduces a novel thermodynamic framework for understanding the glass transition as a space-time phase coexistence phenomenon.

Findings

Glass transition linked to low action tails in fluctuation distributions

Dynamic heterogeneity causes phase coexistence in trajectory space

The transition occurs at a temperature weakly dependent on measurement time

Abstract

We consider the probability distribution for fluctuations in dynamical action and similar quantities related to dynamic heterogeneity. We argue that the so-called "glass transition" is a manifestation of low action tails in these distributions where the entropy of trajectory space is sub-extensive in time. These low action tails are a consequence of dynamic heterogeneity and an indication of phase coexistence in trajectory space. The glass transition, where the system falls out of equilibrium, is then an order-disorder phenomenon in space-time occurring at a temperature T_g which is a weak function of measurement time. We illustrate our perspective ideas with facilitated lattice models, and note how these ideas apply more generally.