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Cooling Rate Dependent Ellipsometry Measurements to Determine the Dynamics of Thin Glassy Films
Published on: January 26, 2016
Dynamical first-order phase transition in kinetically constrained models of glasses
J P Garrahan1, R L Jack, V Lecomte
1School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
Physical Review Letters
|August 7, 2007
Summary
The dynamics of glass formers occur on a first-order coexistence line separating active and inactive phases. This dynamical transition is a generic feature of kinetically constrained models.
Area of Science:
- Condensed matter physics
- Statistical mechanics
- Computational physics
Background:
- Kinetically constrained models (KCMs) are theoretical frameworks used to understand the slow dynamics and glass transition in supercooled liquids.
- These models simplify complex molecular interactions while retaining essential features of cooperative rearrangements.
Purpose of the Study:
- To investigate the nature of the dynamical transition in kinetically constrained models of glass formers.
- To identify the fundamental phase behavior governing the dynamics of these systems.
Main Methods:
- Computation of large-deviation functions for space-time observables, such as the number of configuration changes in a trajectory.
- Analytical calculations using mean-field approximations for dynamic facilitated models.
- Numerical simulations for specific models like the Fredrickson-Andersen model, East model, and constrained lattice gases in various dimensions.
Main Results:
- The dynamics of KCMs were found to occur at a first-order coexistence line between active and inactive dynamical phases.
- This dynamical first-order transition was demonstrated across different KCMs and dimensions.
- The findings suggest a generic mechanism for dynamical transitions in systems exhibiting jamming.
Conclusions:
- A dynamical first-order phase transition is a fundamental characteristic of kinetically constrained models.
- This transition is expected to be present in systems with fully jammed states.
- The study provides a unified framework for understanding the dynamics of various glass-forming systems.
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