Viscoelastic shear stress relaxation in two-dimensional glass forming liquids

Abstract

Translational dynamics of two-dimensional glass forming fluids is strongly influenced by soft, long-wavelength fluctuations first recognized by D. Mermin and H. Wagner. As a result of these fluctuations, characteristic features of glassy dynamics, such as plateaus in the mean squared displacement and the self-intermediate scattering function, are absent in two dimensions. In contrast, Mermin-Wagner fluctuations do not influence orientational relaxation and well developed plateaus are observed in orientational correlation functions. It has been suggested that by monitoring translational motion of particles relative to that of their neighbors, one can recover characteristic features of glassy dynamics and thus disentangle the Mermin-Wagner fluctuations from the two-dimensional glass transition. Here we use molecular dynamics simulations to study viscoelastic relaxation in two and three dimensions. We find different behavior of the dynamic modulus below the onset of slow dynamics (determined by the orientational or cage-relative correlation functions) in two and three dimensions. The dynamic modulus for two-dimensional supercooled fluids is more stretched than for three-dimensional supercooled fluids and it does not exhibit a plateau, which implies the absence of glassy viscoelastic relaxation. At lower temperatures, the two-dimensional dynamic modulus starts exhibiting an intermediate time plateau and decays similarly to the three-dimensional dynamic modulus. The differences in the glassy behavior of two- and three-dimensional glass forming fluids parallel differences in the ordering scenarios in two and three dimensions.

arXiv comment8 pages

References in corpus (13)

• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture I: The van Hove Correlation Function
• Scaling behavior in the $\beta$-relaxation regime of a supercooled Lennard-Jones mixture
• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture II: Intermediate Scattering Function and Dynamic Susceptibility
• Perspective: The Glass Transition
• Mermin-Wagner fluctuations in 2D amorphous solids
• Fundamental differences between glassy dynamics in two and three dimensions
• Configurational entropy measurements in extremely supercooled liquids that break the glass ceiling
• Long Wavelength Fluctuations and the Glass Transition in 2D and 3D
• Zero-temperature glass transition in two dimensions
• Unveiling Dimensionality Dependence of Glassy Dynamics: 2D Infinite Fluctuation Eclipses Inherent Structural Relaxation
• Relationship between bond-breakage correlations and four-point correlations in heterogeneous glassy dynamics: Configuration changes and vibration modes
• Glass transitions may be similar in 2 and 3 dimensions, after all
• Dynamic heterogeneity in two-dimensional supercooled liquids: comparison of bond-breaking and bond-orientational correlations

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• Local Density Fluctuation Governs the Divergence of Viscosity underlying Elastic and Hydrodynamic Anomalies in a 2D Glass-Forming Liquid
• Are supercooled liquids Fickian yet non Gaussian?
• Are strongly confined colloids good models for two dimensional liquids?
• The distinguishable-particle lattice model of glasses in three dimensions
• Kovacs-like memory effect in a sheared colloidal glass: role of non-affine flows
• Long-wavelength fluctuations and dimensionality crossover in confined liquids
• Recursive Algorithm to the Centroid of Free Area for Inherent Structure and Hopping Motion in Deeply Supercooled Binary Hard Disk Systems