Superconducting slab in an antisymmetric magnetic field: Vortex-antivortex dynamics

When a type II superconductor with slab geometry is subjected to a magnetic field which is antisymmetric with respect to the middle of the slab the induced vortex matter consists of vortex-antivortex pairs or double kinks. These double kinks and their role in the generation of a considerable asymmetry in the critical current of the slab are addressed here both numerically, in the framework of time dependent Ginzburg Landau model, and semi-analytically, using the concept of surface energy barriers for flux entry and flux exit.