Ultra-slow and arrested density-fluctuations as precursor of spatial heterogeneity

Dynamical heterogeneities in glass-forming liquids subjected to cooling processes are studied by a theoretical framework based on the non-equilibrium self-consistent generalized Langevin equation theory. This theory predicts that slow cooling rates permit the relaxation to the equilibrium state distinguished by a homogeneous local density. In contrast, fast cooling rates provoke dynamically arrested density-fluctuations and the establishment of permanent spatial heterogeneities even in the presence of density gradients. We further show that the dynamics toward the arrested state has two steps: a truncated relaxation followed by a second relaxation of the diluted part of the system.

Automated summary

This study investigates the dynamical heterogeneities in glass-forming liquids during cooling processes using a theoretical framework. The findings suggest that slow cooling rates lead to the relaxation of the system towards a homogeneous local density equilibrium state, while fast cooling rates result in dynamically arrested density-fluctuations and the formation of permanent spatial heterogeneities even in the presence of density gradients.