The Influence of Surface Defects on Motion of Magnetic Vortices in Mesoscopic Type-II Superconductor with Randomly Distributed Pinning Centers

In the present work, the influences of surface defects on the motion of magnetic vortices in a mesoscopic type-II superconductor with randomly distributed pinning centers are considered using the time-dependent Ginzburg-Landau equations. Two kinds of surface defects are located in the boundary: first, the pinning centers. and second, the geometric defects simultaneously with pinning centers. In the simulation, the magnetization curves, vorticity, and the density of superconducting electrons for both different contents of pinning centers and various geometric defects are analyzed. For the pinning centers as surface defects, the maximum magnetization values as a function of the contents exponentially decrease, and the field \(H_1\) $H_1$ where the first vortex penetrates and the field \(H_2\) $H_2$ where the complete transition from superconducting to a normal state in the system occurs is reduced. For the geometric defects as surface defects, the density of superconducting electrons and the magnetization curves depend on both size and form of them. In addition, a threshold on the size of geometric defects in which the motion of vortices and vorticity changes is presented.