Influence of an applied current on the vortex matter in a superconducting sample with structural defects.

We show how the inclusion of a structural defect of determined geometry controls the vortex state in a square superconducting sample in the presence of an external magnetic field and a current. We simulated the defects by using the deformation parameter , solving the non-lineal time-dependent Ginzburg-Landau equations and using the link variable method, for four different geometries as possible options for the storage vortex, simulating the behavior of a capacitor. We found an exponential dependence of the current in which the first vortex penetrates the sample as a function of the area of a square central defect in the sample.