Robustness of avalanche dynamics in sheared amorphous solids as probed by transverse diffusion

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Physics

Background:

• Amorphous solids exhibit complex mechanical behavior, particularly under shear.
• Understanding plastic events and their correlations is crucial for predicting material failure.
• The influence of temperature on these events near the glass transition remains an active area of research.

Purpose of the Study:

• To investigate the persistence of correlations between elementary plastic events in sheared 2D amorphous solids.
• To analyze the effect of temperature and strain rate on the transverse diffusion coefficient.
• To determine the temperature dependence of the average avalanche size up to the glass transition temperature (T(g)).

Main Methods:

• Extensive numerical simulations of a 2D amorphous solid model.
• Finite-size analysis of the transverse diffusion coefficient.
• Varying strain rates and temperatures up to the supercooled liquid regime.

Main Results:

• Direct qualitative evidence for the persistence of correlations between elementary plastic events.
• Transverse diffusion coefficient analyzed over a broad range of conditions.
• Average avalanche size found to be largely unaffected by temperature up to approximately 0.75T(g).

Conclusions:

• Correlations between plastic events persist significantly even near the glass transition temperature.
• The macroscopic stress behavior is consistent with temperature-insensitivity of avalanche size below 0.75T(g).
• These findings provide insights into the fundamental mechanisms governing deformation in amorphous materials.