1. Viscous liquid dynamics modeled as random walks within overlapping hyperspheres
- Author
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Railton, Mark F. B., Uhre, Eva, Dyre, Jeppe C., and Schrøder, Thomas B.
- Subjects
Condensed Matter - Soft Condensed Matter ,Condensed Matter - Disordered Systems and Neural Networks ,Condensed Matter - Statistical Mechanics - Abstract
The hypersphere model is a simple one-parameter model of the potential energy landscape of viscous liquids, which consists of a percolating system of hyperspheres of equal sizes randomly distributed in $R^{3N}$ where $N$ is the number of particles. We study random walks within overlapping hyperspheres in 12 to 45 dimensions, utilizing an algorithm for on-the-fly placement of the hyperspheres in conjunction with the kinetic Monte Carlo method. We find behavior typical of viscous liquids; thus decreasing the hypersphere density (corresponding to decreasing the temperature) leads to a slowing down of the dynamics by many orders of magnitude. The shape of the mean-square displacement as a function of time is found to be very similar to that of the Kob-Andersen binary Lennard-Jones mixture and the Random Barrier Model, which predicts well the frequency-dependent fluidity of nine glass-forming liquids of different chemistry [Bierwirth et al., Phys. Rev. Lett. 119, 248001 (2017)].
- Published
- 2024