Fabrication and Properties of NdBa 2 Cu 3 O 7-δ /PrBa 2 Cu 3 O 7-δ /NdBa 2 Cu 3 O 7-δ Ramp-Edge Junctions

We discuss recent results on the fabrication process of NdBa2Cu3O7-δ (NBCO) ramp-edge junctions with a PrBa2Cu3O7-δ (PBCO) barrier by pulsed laser deposition (PLD). We examined the influence of different fabrication parameters on the structural quality of the interfaces which significantly affects the transport properties of the junctions. The current-voltage characteristics can be described by the resistively shunted junction model. An IcRn product of 1 mV was obtained at 7 K. It was confirmed that NBCO layers could be incorporated in the multilayer structure without substantial degradation. These devices exhibit IcRn products in a current density regime well suited for SFQ circuit fabrication.