Propagating irreversibility fronts in cyclically sheared suspensions

The interface separating a liquid from its vapor phase is diffuse; the composition varies continuously one to other over finite length. Recent experiments on dynamic jamming fronts in two dimensions [Waitukaitis et al., Europhys. Lett. 102, 44001 (2013)] identified diffuse between jammed and unjammed disks. In both cases, thickness of diverges as critical transition approached. We investigate generality this behavior using third system: A model cyclically sheared non-Brownian suspensions. As we sediment particles toward boundary, observe traveling front that marks irreversible reversible phases. argue width linked diverging correlation length scale bulk, which probe by studying avalanches near criticality. Our results show how interfaces may arise generally when an incompressible brought point.