Defect turbulence in quasi-2D creeping dusty-plasma liquids

We report the intermittent and heterogeneous plastic structural rearrangement at the kinetic level in a quasi-2D creeping dusty-plasma Coulomb liquid through directly tracking each particle trajectory and measuring the evolution of each associated local bond-orientational order. The thermal agitation and external shear have comparable strengths. Their interplay with the Coulomb coupling enhances particle hopping, and induces the loss of local structural memory and avalanche-type excitation of topological defect clusters following the universal scaling behaviors of cluster size in xyt space, akin to the generic behavior of self-organized criticality. Increasing shear tends to reduce the aspect ratio of the temporal to the spatial spans of the defect cluster in xyt space.