Dynamics of particles and cages in an experimental 2D glass former

TL;DR

This study explores the collective and individual particle motions in a 2D colloidal glass former, revealing deviations from standard displacement measures and evidence of cage dynamics and hopping processes.

Contribution

It introduces a novel mean square displacement measure relative to neighbors and demonstrates coupled particle-cage motion and hopping in a 2D colloidal glass.

Findings

Collective particle motions are observed in the 2D glass former.

Deviations from usual MSD highlight complex dynamics.

Evidence of intra-cage hopping processes is found.

Abstract

We investigate the dynamics of a glass forming 2D colloidal mixture and show the existence of collective motions of the particles. We introduce a mean square displacement MSD with respect to the nearest neighbors which shows remarkable deviations from the usual MSD quantifying the individual motion of our particles. Combined with the analysis of the self part of the Van Hove function this indicates a coupled motion of particles with their cage as well as intra cage hopping processes.