Depinning by Fracture in a Glassy Background
  We force a single particle through a two-dimensional simulated glass. We find that the particle velocity obeys a robust power law that persists to drives well above threshold. As the single driven particle moves, it induces cooperative distortions in the surrounding medium. We show theoretically that a fracture model for these distortions produces power law behavior, and discuss implications for experimental probes of soft matter systems. 
M. B. Hastings, C. J. Olson Reichhardt, and C. Reichhardt