Logarithmic Relaxation in a Kinetically Constrained Model
arXiv:cond-mat/0604168 · doi:10.1063/1.2212422
Abstract
We present Monte Carlo simulations in a modification of the north-or-east-or-front model recently investigated by Berthier and Garrahan [J. Phys. Chem. B 109, 3578 (2005)]. In this coarse-grained model for relaxation in supercooled liquids, the liquid structure is substituted by a three-dimensional array of cells. A spin variable is assigned to each cell, with values 0 or 1 denoting respectively unexcited and excited local states in a mobility field. Change in local mobility (spin flip) for a given cell is permitted according to kinetic constraints determined by the mobilities of neighboring cells. In this work we keep the same kinetic constraints of the original model, but we introduce two types of cells (denoted as "fast'' and "slow'') with very different rates for spin flip. As a consequence, fast and slow cells exhibit very different relaxation times for spin correlators. While slow cells exhibit standard relaxation, fast cells display anomalous relaxation, characterized by a concave-to-convex crossover in spin correlators by changing temperature or composition. At intermediate state points logarithmic relaxation is observed over three time decades. These results display striking analogies with dynamic correlators reported in recent simulations on a bead-spring model for polymer blends.
Major changes. To be published in Journal of Chemical Physics
References in corpus (11)
- Geometrical explanation and scaling of dynamical heterogeneities in glass forming systems
- Higher order glass-transition singularities in colloidal systems with attractive interactions
- Nonergodicity transitions in colloidal suspensions with attractive interactions
- Coarse-grained microscopic model of glass formers
- Ideal glass-glass transitions and logarithmic decay of correlations in a simple system
- Glassy timescale divergence and anomalous coarsening in a kinetically constrained spin chain
- Real space origin of temperature crossovers in supercooled liquids
- Logarithmic Relaxation in Glass-Forming Systems
- Logarithmic Relaxation in a Colloidal System
- Is there a higher-order Mode Coupling transition in polymer blends?
- Short-ranged attractions in jammed liquids: How cooling can melt a glass
Cited by in corpus (8)
- Anomalous dynamics of intruders in a crowded environment of mobile obstacles
- Relaxation Scenarios in a Mixture of Large and Small Spheres: Dependence on the Size Disparity
- Multiple glass transitions in star polymer mixtures: Insights from theory and simulations
- Logarithmic decay in single-particle relaxations of hydrated lysozyme powder
- Dynamic facilitation picture of a higher-order glass singularity
- Non-equilibrium dynamics of spin facilitated glass models
- Different scenarios of dynamic coupling in glassy colloidal mixtures
- Anomalous relaxation in binary mixtures: a dynamic facilitation picture