Anatomy of cage formation in a 2D glass-forming liquid

Abstract

The solidity of glassy materials is believed to be due to the cage formed around each particle by its neighbors, but in reality the details of cage-formation remain elusive [1-4]. This cage starts to be formed at the onset temperature/density at which the normal liquid begins to show the first signs of glassy dynamics. To study cage-formation we use here focused lasers to produce a local perturbation of the structure on the particle level in 2D colloidal suspensions and monitor by means of video microscopy the system's non-linear dynamic response. All observables we probed show a response which is non-monotonic as a function of the packing fraction, peaking at the onset density. Video microscopic images reveal that this maximum response is due to the buildup of domains with cooperative dynamics that become increasingly rigid and start to dominate the particle dynamics. This proof-of-concept from microrheological deformation demonstrates that in this glass-forming liquid cage formation is directly related to the merging of these domains, thus elucidating the first step in glass-formation [1, 5].

arXiv comment29 pages, 8 figures

References in corpus (20)

• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture I: The van Hove Correlation Function
• Dynamical heterogeneities in a supercooled Lennard-Jones liquid
• Supercooled Liquids for Pedestrians
• The Physics of the Colloidal Glass Transition
• Probing the equilibrium dynamics of colloidal hard spheres above the mode-coupling glass transition
• Subdiffusion and the cage effect studied near the colloidal glass transition
• Non-monotonic temperature evolution of dynamic correlations in glass-forming liquids
• Long Wavelength Fluctuations and the Glass Transition in 2D and 3D
• Direct measurements of growing amorphous order and non-monotonic dynamic correlations in a colloidal glass-former
• Active and Nonlinear Microrheology in Dense Colloidal Suspensions
• A characteristic energy scale in glasses
• Tests of mode-coupling theory in two dimensions
• Influence of Confinement on Dynamical Heterogeneities in Dense Colloidal Samples
• Cage Size and Jump Precursors in Glass-Forming Liquids: Experiment and Simulations
• Viscoelastic shear stress relaxation in two-dimensional glass forming liquids
• The glass transition of two-dimensional binary soft disk mixtures with large size ratios
• Local melting attracts grain boundaries in colloidal polycrystals
• Critical force in active microrheology
• Local elastic response measured near the colloidal glass transition
• Breakdown of diffusivity-entropy scaling in colloidal glass forming liquids

Cited by in corpus (11)

• Autonomously Probing Viscoelasticity in Disordered Suspensions
• Non-monotonic dynamic correlations beneath the surface of glass-forming liquids
• Different glassy characteristics are related to either caging or dynamical heterogeneity
• Local Plastic Response and Slow Heterogeneous Dynamics of Supercooled Liquids
• Generalized Mode-Coupling Theory for Mixtures of Brownian Particles
• Are strongly confined colloids good models for two dimensional liquids?
• Surface melting of a colloidal glass
• Glass transition in colloidal monolayers controlled by light-induced caging
• Controlling the volume fraction of glass-forming colloidal suspensions using thermosensitive host `mesogels'
• Dynamical arrest in active nematic turbulence
• Stirring supercooled colloidal liquids at the particle scale