Dynamical exchanges in facilitated models of supercooled liquids

Area of Science:

• Condensed Matter Physics
• Statistical Mechanics
• Computational Materials Science

Background:

• Supercooled liquids exhibit complex dynamics near the glass transition.
• Dynamical facilitation models capture generic features of these dynamics.
• Understanding exchange and persistence times is crucial for characterizing glassy behavior.

Purpose of the Study:

• Investigate statistics of dynamical exchange events in coarse-grained models.
• Analyze exchange and persistence times in various spatial dimensions (1, 2, 3).
• Examine the influence of model parameters and temperature on these dynamics.

Main Methods:

• Utilized coarse-grained models based on dynamical facilitation.
• Calculated distributions of exchange times and persistence times.
• Analyzed model behavior for strong and fragile glass formers across temperatures.

Main Results:

• Exchange-time distributions are sensitive to model parameters and dimensions, showing richer behavior than persistence times.
• Mean exchange times exhibit an Arrhenius relationship (tx ~ c^-2) irrespective of model and dimensions.
• Identified and characterized distinct dynamical exchange processes from trajectories.

Conclusions:

• Dynamical facilitation models provide a framework for understanding supercooled liquid dynamics.
• The observed Arrhenius behavior of mean exchange times offers a universal characteristic.
• Findings suggest experimental avenues for validating theoretical predictions on glassy dynamics.