Quantitative Theory of a Time-Correlation Function in a One-Component Glass-Forming Liquid with Anisotropic Potential

Abstract

The Shintani-Tanaka model is a glass-forming system whose constituents interact via anisotropic potential depending on the angle of a unit vector carried by each particle. The decay of time-correlation functions of the unit vectors exhibits the characteristics of generic relaxation functions during glass transitions. In particular it exhibits a 'stretched exponential' form, with the stretching index beta depending strongly on the temperature. We construct a quantitative theory of this correlation function by analyzing all the physical processes that contribute to it, separating a rotational from a translational decay channel. Interestingly, the separate decay function of each of these processes is temperature independent. Taken together with temperature-dependent weights determined a-priori by statistical mechanics one generates the observed correlation function in quantitative agreement with simulations at different temperatures. This underlines the danger of concluding anything about glassy relaxation functions without detailed physical scrutiny.

4 pages, 5 figures

References in corpus (5)

• Ergodicity and Slowing Down in Glass-Forming Systems with Soft Potentials: No Finite-Temperature Singularities
• Statistical Mechanics of the Glass Transition in One-Component Liquids with Anisotropic Potential
• Ageing and Relaxation in Glass Forming Systems
• Quantitative Theory of a Relaxation Function in a Glass-Forming System
• Theory of Relaxation Dynamics in Glass-Forming Hydrogen-Bonded Liquids

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• Randomness-Induced Redistribution of Vibrational Frequencies in Amorphous Solids
• The Effective Temperature in Elasto-Plasticity of Amorphous Solids
• Theory of Specific Heat in Glass Forming Systems
• Non-Universality of the Specific Heat in Glass Forming Systems
• Predictive Statistical Mechanics for Glass Forming Systems