An elastoplastic model approach for the relaxation dynamics of active glasses

Area of Science:

• Physics
• Materials Science
• Soft Matter Physics

Background:

• Understanding how activity influences glassy dynamics is vital for biological processes.
• Active glasses present unique phenomena and extend the study of equilibrium glass-forming liquids.

Purpose of the Study:

• To introduce novel approaches for investigating relaxation dynamics in active glasses using an active elastoplastic model (EPM).
• To analyze the distinct contributions of activity-mediated yielding, barrier crossing, and rotational dynamics to glass behavior.

Main Methods:

• Development and application of a family of active elastoplastic models (EPMs).
• Investigation of relaxation dynamics through local plastic yielding.
• Incorporation of activity via three key features: active yielding, activated barrier crossing, and persistent rotational dynamics.

Main Results:

• The minimal active EPM successfully replicates known active glass behaviors and aligns with analytical results for low activity.
• Active yielding is identified as the primary driver of relaxation dynamics.
• Persistence in the yielding direction is shown to govern dynamic heterogeneity in active glasses.

Conclusions:

• The active EPM provides a framework to separately study various aspects of active glass dynamics.
• The model highlights the distinct roles of active yielding and yielding direction persistence in governing the complex behaviors of active glasses.