YBa2Cu3O7 thin film step junctions

Abstract We report the fabrication of high T c step junctions with high critical current densities on MgO substrates. They carry Josephson currents up to ≈82K. The magnetic field dependence of the critical current shows conventional sinc function like modulation just below T c . At lower temperatures the junctions are so strongly coupled that they are large compared to the Josephson penetration depth.