Plastic Deformation in Microscopic Colloidal Crystals

Plastic flow in microscopic two-dimensional colloidal crystals is analyzed by means of numerical simulations and analytical modeling. At such scales, irreversible deformation is mediated by a small number of dislocations and no dislocation storage phenomena are observed. We study the size distributions of plastic avalanches and we find them to be governed by anomalous exponents. We observe a non-trivial dependence of the yield stress on the systems size and prove that it can be explained in terms of the interactions of dislocations with rigid walls, which become crucial at such length scales.