Manifestations of Dynamical Facilitation in Glassy Materials

Abstract

By characterizing the dynamics of idealized lattice models with a tunable kinetic constraint, we explore the different ways in which dynamical facilitation manifests itself within the local dynamics of glassy materials. Dynamical facilitation is characterized both by a mobility transfer function, the propensity for highly-mobile regions to arise near regions that were previously mobile, and by a facilitation volume, the effect of an initial dynamical event on subsequent dynamics within a region surrounding it. Sustained bursts of dynamical activity -- avalanches -- are shown to occur in kinetically constrained models, but, contrary to recent claims, we find that the decreasing spatiotemporal extent of avalanches with increased supercooling previously observed in granular experiments does not imply diminishing facilitation. Viewed within the context of existing simulation and experimental evidence, our findings show that dynamical facilitation plays a significant role in the dynamics of systems investigated over the range of state points accessible to molecular simulations and granular experiments.

10 pages, 5 figures

References in corpus (8)

• Theoretical perspective on the glass transition and amorphous materials
• Glassy dynamics of kinetically constrained models
• Irreversible reorganization in a supercooled liquid originates from localised soft modes
• Spatial correlations in the dynamics of glassforming liquids: Experimental determination of their temperature dependence
• Excitation lines and the breakdown of Stokes-Einstein relations in supercooled liquids
• The building blocks of dynamical heterogeneities in dense granular media
• Dynamical Exchanges in Facilitated Models of Supercooled liquids
• Properties of ideal Gaussian glass-forming systems

Cited by in corpus (19)

• Perspective: The Glass Transition
• Direct measurements of growing amorphous order and non-monotonic dynamic correlations in a colloidal glass-former
• Growing Dynamical Facilitation on Approaching the Random Pinning Colloidal Glass Transition
• Heterogeneous relaxation dynamics in amorphous materials under cyclic loading
• Theory of amorphous ices
• Deconstructing the glass transition through critical experiments on colloids
• Elastoplasticity Mediates Dynamical Heterogeneity Below the Mode-Coupling Temperature
• Dynamical facilitation governs glassy dynamics in suspensions of colloidal ellipsoids
• Fluctuating Mobility Generation and Transport in Glasses
• Induced cooperative motions in a medium driven at the nanoscale: Searching for an optimum excitation period
• Using the s-Ensemble to Probe Glasses Formed by Cooling and Aging
• Folding time dependence of the motions of a molecular motor diluted inside an amorphous medium
• Comparison of time reversal symmetric and asymmetric nano-swimmers oriented with an electric field in soft matter
• Meta-work and the analogous Jarzynski relation in ensembles of dynamical trajectories
• Transmission of mobility via cooperative mechanisms in soft active matter
• Dynamic phase transition induced by active molecules simulating a facilitation mechanism in a supercooled liquid
• How do packing defects modify the cooperative motions in supercooled liquids ?
• Simulation of a flat folding nano-swimmer confined in a nanopore
• A facilitation-induced fluidization transition in supercooled water triggered by a few active molecules