Dynamic Coarsening

Crystal surfaces led out of equilibrium by a growth or erosion process may undergo morphological instabilities and develop distinct structures: ondulations, mounds or pyramids, bunches of steps, ripples.

Emergent pattern may increase in size with time by means of a coarsening process which may continue forever or stop at some relevant length scale.

Paolo Politi’s group has studied the dynamics for three different types of instabilities, stressing the main physical ingredients: kinetic, energetic and athermal instabilities. Coarsening at crystal surfaces is the subject of a recent review paper in a special issue of Comptes Rendus Physique, which deals, more generally, with coarsening dynamics in different fields, from active matter to pattern forming systems, from granular materials to fluids.