Comment on "Correlation between Dynamic Heterogeneity and Medium-Range Order in Two-Dimensional Glass-Forming Liquids"

TL;DR

This paper critiques a recent study on 2D glass-forming liquids, questioning the interpretation of the relationship between relaxation dynamics, medium-range order, and dynamic heterogeneities.

Contribution

It provides a critical analysis challenging the original interpretation of the correlation between dynamic heterogeneity and medium-range order in 2D glass-formers.

Findings

Questions the direct correlation between relaxation slowdown and medium-range order.

Highlights potential alternative explanations for observed phenomena.

Emphasizes importance of careful interpretation in glass transition studies.

Abstract

In a recent letter, Kawasaki et al. (PRL 99, 215701 (2007)) study glass formation in a 2-dimensional (2D) model of polydisperse repulsive disks. They give numerical evidence for a direct relation between slowing down of the relaxation, extension of some medium-range order, and development of dynamic heterogeneities. We disagree with the authors' interpretation on two points which we believe to be potentially important for understanding the glass transition.