Two-time correlations for probing the aging dynamics of glassy colloids

Area of Science:

• Physics
• Materials Science
• Computational Science

Background:

• Colloidal systems exhibit complex aging dynamics.
• Simulating aging dynamics at high densities has been computationally challenging.
• Understanding relaxation mechanisms is crucial for materials science.

Purpose of the Study:

• To investigate the aging dynamics of dense 2D colloidal systems.
• To explore the underlying mechanisms driving relaxation and rearrangement events.
• To validate a theoretical model based on record dynamics against simulation data.

Main Methods:

• Molecular dynamics simulations of dense 2D colloidal systems.
• Quenching systems to densities above the glass transition.
• Utilizing Voronoi tessellations to identify irreversible particle rearrangement events.
• Analyzing the van-Hove function to study particle displacement statistics.

Main Results:

• The rate of irreversible events decelerates hyperbolically over time.
• Particle displacements show a data collapse as a function of t/tw, indicating aging.
• The observed dynamics are consistent with a model based on record dynamics.
• An on-lattice model based on record dynamics accurately reproduces simulation results.

Conclusions:

• Aging dynamics in dense 2D colloidal systems are governed by record dynamics.
• Record dynamics provide a comprehensive explanation for observed relaxation behaviors.
• The findings offer a new perspective on understanding aging in disordered materials.