Avalanche criticality emerges by thermal fluctuation in a quiescent glass.

Abstract

We investigate the avalanche dynamics of thermal relaxation in glassy systems after a rapid quench by molecular simulation. We find that the particle rearrangements show local rearrangements with long-range quadrupolar displacements, and their sizes follow a power-law distribution satisfying a simple scaling relation. These results imply the relation between thermal relaxation of glassy systems, and avalanches in sheared amorphous solids and a recent theory on the thermal elastoplastic model. However, we also observe the properties unpredicted by the previous theories, including the smaller exponent of the distribution and the non-power-law growth of avalanche size against system size. Our results suggest that by viewing a glass as a thermally driven elastoplastic material, we can understand dynamics below the glass transition point, such as aging.