Microrheology of supercooled liquids in terms of a continuous time random walk

TL;DR

This paper uses molecular dynamics simulations and a continuous time random walk framework to analyze the microrheology of supercooled liquids, revealing the physical origins of their linear and nonlinear responses.

Contribution

It introduces a novel approach combining metabasin analysis with CTRW to interpret microrheological responses in supercooled liquids.

Findings

Identification of critical forces in supercooled liquids.

Correlation of linear and nonlinear responses with CTRW dynamics.

Validation of theoretical predictions with simulation results.

Abstract

Molecular dynamics simulations of a glass-forming model system are performed under application of a microrheological perturbation on a tagged particle. The trajectory of that particle is studied in its underlying potential energy landscape. Discretization of the configuration space is achieved via a metabasin analysis. The linear and nonlinear responses of drift and diffusive behavior can be interpreted and analyzed in terms of a continuous time random walk. In this way the physical origin of linear and nonlinear response can be identified. Critical forces are determined and compared with predictions from literature.