Universal activated aging and weak ergodicity breaking in spin and structural glasses

TL;DR

This paper introduces a generalized trap model for activated aging in glasses, revealing universal weak ergodicity breaking prior to strong ergodicity breaking, supported by tests on spin and structural glasses, and proposes a unified phase diagram.

Contribution

The paper develops a generalized trap model linking energy landscape properties to aging dynamics, and demonstrates its universality across different glassy systems.

Findings

Weak ergodicity breaking occurs before strong ergodicity breaking during cooling.

The size of activation clusters can be inferred from the decay of correlation functions.

The model's predictions are validated in spin glasses and structural glasses, including silica.

Abstract

Glasses possess complex energy landscapes and exhibit non-equilibrium aging dynamics. Here, we propose a generalized trap model for activated aging based on a key static property of the energy landscape: the distribution of energy barriers. Our theory predicts that, upon cooling, weak ergodicity breaking (WEB) in quenching dynamics occurs prior to strong ergodicity breaking in equilibrium dynamics. Furthermore, the theory indicates that the characteristic size of activation clusters can be deduced from the logarithmic decay of the time-correlation function. We rigorously test the model's assumptions and predictions using the simplest spin glass model - the random energy model. The predicted aging behavior is also universally observed in paradigmatic structural glasses, including the Weeks-Chandler-Andersen (WCA) model and amorphous silica. Remarkably, applying our framework to the WCA model allows us to extract a static length from the non equilibrium dynamics, extending its observable growth range from a mere factor of 2-3 to a full order of magnitude and providing supportive evidence for the random first-order transition scenario. Finally, we propose a unified ergodic-WEB phase diagram for aging dynamics in general glassy systems.