Glass Transition of Hard Sphere Systems: Molecular Dynamics and Density Functional Theory

TL;DR

This paper investigates the glass transition in hard sphere systems using density functional theory and molecular dynamics, revealing a metastable amorphous state and a sharp slowdown in relaxation near the transition density.

Contribution

It combines molecular dynamics simulations with density functional theory to analyze the glass transition and identifies a metastable amorphous state emerging at high density.

Findings

Identification of a metastable amorphous state at high density.

Observation of sharp slowing down of alpha relaxation near the transition.

Correlation between free energy minima and dynamical slowdown.

Abstract

The glass transition of a hard sphere system is investigated within the framework of the density functional theory (DFT). Molecular dynamics (MD) simulations are performed to study dynamical behavior of the system on the one hand and to provide the data to produce the density field for the DFT on the other hand. Energy landscape analysis based on the DFT shows that there appears a metastable (local) free energy minimum representing an amorphous state as the density is increased. This state turns out to become stable, compared with the uniform liquid, at some density, around which we also observe sharp slowing down of the $alpha$ relaxation in MD simulations.