A crossover in spatio-temporal correlations of strain fluctuations in glass forming liquids

Abstract

Via molecular dynamics simulations of a generic glass former in the liquid state, 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/lc) at intermediate distances. The characteristic length of the exponential decay grows both with temperature and time via, l 2 c ∝ 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.

Preface: Special issue ‘Unifying Concepts in Glass Physics VII’

“…Other topics in supercooled liquids approaching their glass transition addressed here include density fluctuations, which are often overlooked in glassforming systems [11], Stokes-Einstein relations [12], mean-field theories [13] and configuration-tree theory [14]. Far-from equilibrium phenomena tackled in this special issue range from aging and rejuvenation in the novel context of colloidal experiments [15] to strain fluctuations [16].…”