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

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.