Microscopic Analysis of Flux Structure in a Dirty Superconductor

Using the Bogoliubov-de Gennes equations with an impurity potential and the finite element method, we obtain vortex structures in a square dirty superconducting plate under an external magnetic field. Size of vortex core structure depends on the size of the impurity potential. In order to clarify origins of the relations of vortex core and impurity sizes, we examine quasi-particle structures, especially bound states around the vortex core. Then we show how microscopic structure affects the vortex structure that is pinned at the impurity.