Defect dynamics during a quench in a Benard-Marangoni convection system

We report experimental evidence of defect formation and dynamics in a symmetry breaking transition for a conduction-convection Benard-Marangoni system. As opposite to the behavior of perfect patterns, defects appear to interact in a spatial region, responsible for the formation of bounded states that survive much longer than the characteristic time scales. The analysis of the transient defect dynamics allows to define this defect interaction region in the space, giving rise to penta-hepta-like defects on top of the hexagonal pattern. Other defect configurations are shown to disappear rapidly either through dislocations moving toward the boundaries or through dislocation-dislocation annihilation. This evidence suggests that the scaling law of defects in the final structure versus quench time might be investigated by analyzing the probability of two or more dislocations to appear in the same interaction region.