Considerable enhancement of the critical current in a superconducting film by a magnetized magnetic strip

Abstract

We show that a magnetic strip on top of a superconducting strip magnetized in a specified direction may considerably enhance the critical current in the sample. At fixed magnetization of the magnet we observed the diode effect---the value of the critical current depends on the direction of the transport current. We explain these effects by a influence of the nonuniform magnetic field induced by the magnet on the current distribution in the superconducting strip. The experiment on a hybrid $\mathrm{Nb}∕\mathrm{Co}$ structure confirmed the predicted variation of the critical current with a changing value of magnetization and direction of the transport current.