Two regimes of vortex penetration into platelet-shaped type-II superconductors

Vortex penetration into a thin superconducting strip of a rectangular cross section is considered at an increasing applied magnetic field H _a, taking an interplay between the Bean-Livingston and the geometric barriers in the sample into account. We calculate the magnetic field H _p at which the penetration begins and show that two regimes of vortex penetration are possible. In the first regime, vortices appearing at the corners of the strip at H _a = H _p immediately move to its center, where a vortex dome starts to develop. In the second regime, the penetration occurs in two stages. In the first stage, at H _a < H _p, tilted vortices penetrate into the edge regions of the strip, where novel domes are shown to be formed at the top, bottom, and lateral surfaces. In the second stage, at H _a = H _p, the vortex propagation to the center becomes possible. The difference between the regimes manifests itself in slightly different dependences of the magnetic moment of the strip on H _a .