Multi-component generalized mode-coupling theory: Predicting dynamics from structure in glassy mixtures

TL;DR

This paper extends generalized mode-coupling theory (GMCT) to multi-component systems, enabling better predictions of glassy dynamics in complex mixtures by incorporating higher order correlations, thus advancing understanding of the glass transition.

Contribution

The paper develops GMCT for multi-component systems, improving its predictive accuracy for complex glass-forming mixtures beyond single-component limitations.

Findings

GMCT hierarchy levels enhance predictive power.

Accurate modeling of binary Lennard-Jones mixture dynamics.

Insights into the role of attraction in supercooled liquids.

Abstract

The emergence of glassy dynamics and the glass transition in dense disordered systems is still not fully understood theoretically. Mode-coupling theory (MCT) has shown to be effective in describing some of the non-trivial features of glass formation, but it cannot explain the full glassy phenomenology due to the strong approximations on which it is based. Generalized mode-coupling theory (GMCT) is a hierarchical extension of the theory, which is able to outclass MCT by carefully describing the dynamics of higher order correlations in its generalized framework. Unfortunately, the theory has so far only been developed for single component systems and as a result works poorly for highly polydisperse materials. In this paper, we solve this problem by developing GMCT for multi-component systems. We use it to predict the glassy dynamics of the binary Kob-Andersen Lennard-Jones mixture, as well as its purely repulsive Weeks-Chandler-Andersen analogue. Our results show that each additional level of the GMCT hierarchy gradually improves the predictive power of GMCT beyond its previous limit. This implies that our theory is able to harvest more information from the static correlations, thus being able to better understand the role of attraction in supercooled liquids from a first-principles perspective.