Detecting temporal correlations in hopping dynamics in Lennard–Jones liquids
Metadatos
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Institute of Physics
Materia
Glassy systems Hopping dynamics Jump detection Rare events
Fecha
2022-07-21Referencia bibliográfica
Vittoria Sposini... [et al.] 2022 J. Phys. A: Math. Theor. 55 324003. [https://doi.org/10.1088/1751-8121/ac7e0a]
Patrocinador
European Commission European Commission Joint Research Centre 847693 840195-ARIADNE; Polish National Agency for Academic Exchange (NAWA)Resumen
Lennard–Jones mixtures represent one of the popular systems for the study
of glass-forming liquids. Spatio/temporal heterogeneity and rare (activated)
events are at the heart of the slow dynamics typical of these systems. Such slow
dynamics is characterised by the development of a plateau in the mean-squared
displacement (MSD) at intermediate times, accompanied by a non-Gaussianity
in the displacement distribution identified by exponential tails. As pointed out
by some recent works, the non-Gaussianity persists at times beyond the MSD
plateau, leading to a Brownian yet non-Gaussian regime and thus highlighting
once again the relevance of rare events in such systems. Single-particle motion
of glass-forming liquids is usually interpreted as an alternation of rattlingwithin
the local cage and cage-escape motion and therefore can be described as a
sequence of waiting times and jumps. In this work, by using a simple yet robust
algorithm, we extract jumps and waiting times from single-particle trajectories
obtained via molecular dynamics simulations. We investigate the presence
of correlations between waiting times and find negative correlations, which
becomes more and more pronounced when lowering the temperature.