Vortex Interactions and Clustering in Thin Superconductors.

Cluster formation is a focus of interdisciplinary research in both chemistry and physics. Here we discuss the exotic example of this phenomenon in the vortex matter of a thin superconductor. In superconducting films, the clustering takes place because of particular properties of the vortex interactions in the crossover or intertype regime between superconductivity types I and II. These interactions are controlled by the two parameters that are responsible for the crossover, Ginzburg-Landau parameter κ, which specifies the superconducting material of the film, and film thickness , which controls effects due to stray magnetic fields outside the sample. We demonstrate that their competition gives rise to a complex spatial dependence of the interaction potential between vortices, favoring the formation of chainlike vortex clusters.