Length scale dependence of the Stokes-Einstein and Adam-Gibbs relations in model glass formers

Abstract

The Adam-Gibbs (AG) relation connects the dynamics of a glass-forming liquid to its the thermodynamics via. the configurational entropy, and is of fundamental importance in descriptions of glassy behaviour. The breakdown of the Stokes-Einstein (SEB) relation between the diffusion coefficient and the viscosity (or structural relaxation times) in glass formers raises the question as to which dynamical quantity the AG relation describes. By performing molecular dynamics simulations, we show that the AG relation is valid over the widest temperature range for the diffusion coefficient and not for the viscosity or relaxation times. Studying relaxation times defined at a given wavelength, we find that SEB and the deviation from the AG relation occur below a temperature at which the correlation length of dynamical heterogeneity equals the wavelength probed.

References in corpus (8)

• Growing length and time scales in glass forming liquids
• Fractional Stokes-Einstein and Debye-Stokes-Einstein relations in a network forming liquid
• Hopping and the Stokes-Einstein relation breakdown in simple glass formers
• Coupling/decoupling between translational and rotational dynamics in a supercooled molecular liquid
• The role of structure and entropy in determining differences in dynamics for glass formers with different interaction potentials
• Connections of activated hopping processes with the breakdown of the Stokes-Einstein relation and with aspects of dynamical heterogeneities
• Dynamic phase coexistence in glass-forming liquids
• Viscoelasticity and Stokes-Einstein relation in repulsive and attractive colloidal glasses

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• A Novel Method to Probe the Pronounced Growth of Correlation Lengths in an Active Glass-forming Liquids using Elongated Probe
• Is the glassy dynamics same in 2D as in 3D? The Adam Gibbs relation test