Local thermal energy as a structural indicator in glasses

Abstract

Identifying heterogeneous structures in glasses --- such as localized soft spots --- and understanding structure-dynamics relations in these systems remain major scientific challenges. Here we derive an exact expression for the local thermal energy of interacting particles (the mean local potential energy change due to thermal fluctuations) in glassy systems by a systematic low-temperature expansion. We show that the local thermal energy can attain anomalously large values, inversely related to the degree of softness of localized structures in a glass, determined by a coupling between internal stresses --- an intrinsic signature of glassy frustration ---, anharmonicity and low-frequency vibrational modes. These anomalously large values follow a fat-tailed distribution, with a universal exponent related to the recently observed universal ${\omega }^4$ density of states of quasi-localized low-frequency vibrational modes. When the spatial thermal energy field --- a `softness field' --- is considered, this power-law tail manifests itself by highly localized spots which are significantly softer than their surroundings. These soft spots are shown to be susceptible to plastic rearrangements under external driving forces, having predictive powers that surpass those of the normal-modes-based approach. These results offer a general, system/model-independent, physical-observable-based approach to identify structural properties of quiescent glasses and to relate them to glassy dynamics.

8 pages, 4 figures + Supporting Information, shorter title, minor textual changes

References in corpus (14)

• Theoretical perspective on the glass transition and amorphous materials
• Supercooled Liquids for Pedestrians
• Irreversible reorganization in a supercooled liquid originates from localised soft modes
• The role of local structure in dynamical arrest
• Identifying structural flow defects in disordered solids using machine learning methods
• Strain localization and percolation of stable structure in amorphous solids
• Continuum limit of the vibrational properties of amorphous solids
• Understanding fragility in supercooled Lennard-Jones mixtures. I. Locally preferred structures
• Structure and dynamics in glass-formers: predictability at large length scales
• Identification of long-lived clusters and their link to slow dynamics in a model glass former
• Structural and dynamical heterogeneity in a glass forming liquid
• Predicting plasticity with soft vibrational modes: from dislocations to glasses
• Nonlinear modes disentangle glassy and Goldstone modes in structural glasses
• On the spatial distribution of thermal energy in equilibrium

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• Low-energy quasilocalized excitations in structural glasses
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• A characteristic energy scale in glasses
• Anomalous vibrational properties in the continuum limit of glasses
• Effect of instantaneous and continuous quenches on the density of vibrational modes in model glasses
• Fast Dynamics in a Model Metallic Glass-forming Material
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• Frustration-induced internal stresses are responsible for quasilocalized modes in structural glasses
• Topology of vibrational modes predict plastic events in glasses
• Universal disorder-induced broadening of phonon bands: from disordered lattices to glasses
• Nonlinear quasilocalized excitations in glasses. I. True representatives of soft spots
• Attractive versus truncated repulsive supercooled liquids: The dynamics is encoded in the pair correlation function
• Solid-that-flows picture of glass-forming liquids
• Anisotropic Structural Predictor in Glassy Materials
• Machine Learning Characterization of Structural Defects in Amorphous Packings of Dimers and Ellipses
• Low-frequency excess vibrational modes in two-dimensional glasses
• Dilatancy of Shear Transformations in a Colloidal Glass
• Atomic nonaffinity as a predictor of plasticity in amorphous solids
• Instabilities of jammed packings of frictionless spheres under compression
• Combining Machine Learning and Physics to Understand Glassy Systems
• Experimental and Numerical Verification of Anomalous Screening Theory in Granular Matter
• Edwards field theory for glasses and granular matter
• Correlation of plastic events with local structure in jammed packings across spatial dimensions
• Extracting the properties of quasilocalized modes in computer glasses: Long-range continuum fields, contour integrals and boundary effects
• Nonphononic spectrum of two-dimensional structural glasses
• Density of States below the First Sound Mode in 3D Glasses
• Exploring the link between crystal defects and non-affine displacement fluctuations
• Statistical mechanics of local force dipole responses in computer glasses
• Internally-stressed and positionally-disordered minimal complexes yield glasslike nonphononic excitations
• Renormalization of elastic quadrupoles in amorphous solids
• Microscopic Theory of the Elastic Shear Modulus and Length-Scale-Dependent Dynamic Re-Entrancy Phenomena in Very Dense Sticky Particle Fluids
• Hedgehog topological defects in 3D amorphous solids
• Inferring the particle-wise dynamics of amorphous solids from the local structure at the jamming point
• Elementary processes in dilatational plasticity of glasses
• Structural, mechanical, and vibrational properties of particulate physical gels