Connecting short and long time dynamics in hard-sphere-like colloidal glasses

TL;DR

This study investigates the microscopic cage-jump dynamics in a 2D colloidal suspension, revealing that volume fraction influences these features similarly to temperature effects in molecular glasses, enabling short-term diffusivity predictions.

Contribution

It provides experimental evidence linking cage-jump dynamics to volume fraction in colloids, extending understanding from molecular to colloidal glass formers.

Findings

Cage-jump features depend on volume fraction.

Short-time predictions of diffusivity are possible from cage dynamics.

Dynamics show similarities between colloidal and molecular glasses.

Abstract

Glass-forming materials are characterized by an intermittent motion at the microscopic scale. Particles spend most of their time rattling within the cages formed by their neighbors, and seldom jump to a different cage. In molecular glass formers the temperature dependence of the jump features, such as the average caging time and jump length, characterizes the relaxation processes and allows for a short-time prediction of the diffusivity. Here we experimentally investigate the cage-jump motion of a two-dimensional hard-sphere-like colloidal suspension, where the volume fraction is the relevant parameter controlling the slowing down of the dynamics. We characterize the volume fraction dependence of the cage-jump features and show that, as in molecular systems, they allow for a short time prediction of the diffusivity.