Fabrication of heteroepitaxial YBa2Cu3O7−x-PrBa2Cu3O7−x-YBa2Cu3O7−x Josephson devices grown by laser deposition

We have fabricated Josephson weak links from in situ laser-deposited four-layer structures of YBa2Cu3O7−x/PrBa2Cu3O7−x/YBa2Cu3O7−xAu. These devices show superconductor/normal-metal/superconductor-like current-voltage characteristics with good areal scaling of both the critical currents Ic and resistances Rj, with IcRj≊3.5 mV. Constant-voltage current steps observed in response to 84 GHz mm-wave radiation and modulation of the dc supercurrent in a transverse magnetic field demonstrate that both the ac and dc Josephson effects occur in these devices.