Anomalous diffusion of driven particles in supercooled liquids

TL;DR

This paper investigates the superdiffusive behavior of a driven particle in a supercooled liquid through simulations, revealing long-time enhanced diffusion and non-Gaussian dynamics explained by a continuous time random walk model.

Contribution

It provides a quantitative analysis of superdiffusivity in driven particles and links non-equilibrium superdiffusive behavior to equilibrium non-Gaussian parameters.

Findings

Superdiffusive behavior observed at intermediate times.

Giant long-time diffusivity in driven particles.

Connection between non-equilibrium superdiffusivity and equilibrium non-Gaussianity.

Abstract

We have performed non-equilibrium dynamics simulations of a binary Lennard-Jones mixture in which an external force is applied on a single tagged particle. For the diffusive properties of this particle parallel to the force superdiffusive behavior at intermediate times as well as giant long-time diffusivity is observed. A quantitative description of this non-trivial behavior is given by a continuous time random walk analysis of the system in configuration space. We further demonstrate, that the same physical properties which are responsible for the superdiffusivity in non-equilibrium systems also determine the non-Gaussian parameter in equilibrium systems.