Annealing and rejuvenation in a two-dimensional model amorphous solid under oscillatory shear

Area of Science:

• Condensed Matter Physics
• Materials Science
• Statistical Mechanics

Background:

• Amorphous solids display unique mechanical properties distinct from crystalline solids.
• Understanding the response of amorphous solids to external stimuli like shear is crucial for materials design.
• Annealing and rejuvenation are key processes influencing the stability and behavior of amorphous materials.

Purpose of the Study:

• To investigate the annealing and rejuvenation behavior of a 2D amorphous solid model under oscillatory shear.
• To determine the influence of initial cooling protocols on the material's response.
• To explore the applicability of random energy landscape models for describing amorphous solid dynamics.

Main Methods:

• Simulations of a two-dimensional amorphous solid model subjected to oscillatory shear.
• Varying cooling protocols to generate different initial configurations.
• Modeling the system's dynamics using a forced dynamics model on a random energy landscape.

Main Results:

• Subyield oscillatory shear leads to energy decrease or increase depending on the initial cooling protocol.
• Post-yield oscillatory shear results in a consistent energy increase, independent of initial conditions.
• The random energy landscape model qualitatively reproduces simulation results for mean potential energy and mean-square displacement.

Conclusions:

• The dynamics of amorphous solids under oscillatory shear are sensitive to initial conditions and shear regime (subyield vs. post-yield).
• Random energy landscape models provide a simplified yet effective framework for understanding key aspects of amorphous solid dynamics.
• Complex real-space interactions may not be essential for capturing fundamental behaviors like energy changes and particle displacement in these systems.