Anomalous diffusion in supercooled liquids: a long-range localisation in particle trajectories

TL;DR

This paper investigates particle trajectories in supercooled liquids, revealing a novel long-range localisation phenomenon linked to the energy landscape's structure, which differs from traditional short-range cage effects.

Contribution

It introduces the concept of long-range localisation in particle trajectories and connects it to the potential-energy landscape in fragile glass-formers, providing new insights into diffusion anomalies.

Findings

Discovery of long-range localisation in particle trajectories

Link between localisation and energy landscape topography

Differences observed between two fragile glass-forming liquids

Abstract

A statistical analysis of the geometries of particle trajectories in the supercooled liquid state is reported. We examine two structurally different fragile glass-forming liquids simulated by molecular dynamics. In both liquids, the trajectories are found to exhibit a long-range localisation distinct from the short-range localisation within the cage of nearest neighbours. This novel diffusion anomaly is interpreted as a result of the potential-energy landscape topography of fragile glass-formers where the local energy minima coalesce into metabasins - compact domains with low escape probability.