Scale-Bridging Thermodynamic and Kinetic Simulation (STKS)
A crossover in spatio-temporal correlations of strain fluctuations in glass forming liquids
M. R. Hassani, M. M. Bruns, F. Varnik.
Journal of Statistical Mechanics: Theory and Experiment (JSTAT), 2020, 014002, (2020)
Via molecular dynamics simulations of a generic glass former in the supercooled and normal liquid states, it is shown that spatial correlations of strain fluctuations exhibit a crossover from the well-established power-law ~1/r^3-decay at long wavelengths to an exponential behavior, ~exp(-r/l_c) at intermediate distances. The characteristic length of the exponential decay grows both with temperature and time via,l_c \propto D(T)t , with D(T) being the temperature-dependent diffusion coefficient. This suggests that the crossover between the power-law and exponential decays is governed by a diffusion process.
Keyword(s): correlation functions, glasses (structural), plasticity, molecular dynamics