Soft Matter and Complex Systems Seminar

The talk will address the dynamics of a probe particle driven by a constant forcethrough a colloidal glass of hard spheres. This nonequilibrium andanisotropic problem is investigated using a new implementation of themode-coupling approximation with multiple relaxation channels andLangevin dynamics simulations. An important feature of the system isthe critical force, above which the probe delocalizes. Frictioncoefficients of delocalized probes decrease with force, indicatingforce-thinning behavior. Probe van Hove functions predicted by thetheory show exponential tails reminiscent of an intermittent dynamicsof the probe. This scenario is microscopically supported bysimulations.