Computer Simulation Study on Confined Vortex Matter

The so-called magic number configurations have been studied for several decades in a wide variety of systems where confinement is important. Recent progress in nanoscale patterning of superconducting films and single crystals provides unprecedented control of the size and shape of nanoscale superconducting samples and allows for the experimental study of confined superconducting vortex matter. In order to explore theoretically the properties of confined vortex matter, we are using computational methods developed for Lennard-Jones clusters, and we are able to explore the energy landscapes of vortex systems as well. Furthermore, we propose an analysis based on a network representation of the energy landscape, with metastable states being represented by nodes and the transition states between adjacent local minima as edges. We predict the emergence of magic number configuration by studying the metastable states and transition states of a finite number of vortices confined by containers of different geometry. Our results agree well with recent experiments.