Field induced superconductivity in magnetically modulated films

The transport properties of Al superconducting thin films covering arrays of Co/Pt pinning centers of two different sizes are measured and compared. Detailed magnetization characterization of the dots allow us to gain control over the average magnetization of the dots through the application of an external magnetic field. By increasing the magnetization of the dots a gradually increasing shift of the superconducting phase boundary is observed. This shift is explained in terms of vortex-antivortex pair generation. It is shown that the resulting field-induced-superconductivity is strongly dependent on the size of the magnetic dots