Exploring canyons in glassy energy landscapes using metadynamics

TL;DR

This paper introduces a modified metadynamics algorithm that efficiently explores low energy regions of complex glassy energy landscapes, revealing canyon structures and enabling the study of dense and low-energy states in model glass formers.

Contribution

A novel modified metadynamics method for exploring high-dimensional energy landscapes of glassy systems, uncovering canyon structures and low-energy configurations.

Findings

Identified canyon structures in energy landscapes of model foam, hard sphere fluids, and Kob-Andersen glass.

Successfully sampled high-density configurations beyond the jamming transition.

Approached the Kauzmann limit in low-energy states with modest computational effort.

Abstract

The complex physics of glass forming systems is controlled by the structure of the low energy portions of their potential energy landscapes. Here, we report that a modified metadynamics algorithm efficiently explores and samples low energy regions of such high-dimensional landscapes. In the energy landscape for a model foam, our algorithm finds and descends meandering `canyons' in the landscape, which contain dense clusters of energy minima along their floors. Similar canyon structures in the energy landscapes of two model glass formers -- hard sphere fluids and the Kob-Andersen glass -- allow us to reach high densities and low energies, respectively. In the hard sphere system, fluid configurations are found to form continuous regions that cover the canyon floors up to densities well above the jamming transition. For the Kob-Andersen glass former, our technique samples low energy states with modest computational effort, with the lowest energies found approaching the predicted Kauzmann limit.