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

Muhammad Hassani; Marian Bruns; Fathollah Varnik

doi:10.1088/1742-5468/ab5366

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arXiv · 1907.02794

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

Muhammad Hassani·Marian Bruns·Fathollah Varnik

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Abstract

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 $\sim 1/r^3$-decay at long wavelengths to an exponential behavior, $\sim \exp(-r/l_{\text {c}})$ at intermediate distances. The characteristic length of the exponential decay grows both with temperature and time via, $l_{\text {c}}^2 \propto D(T)\, t$, 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.

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Muhammad Hassani, Marian Bruns, Fathollah Varnik. 2019-07-05. A crossover in spatio-temporal correlations of strain fluctuations in glass forming liquids. https://doi.org/10.1088/1742-5468%2Fab5366

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