Applied Physics Letters · 1996 · 66 citations · 1 references
Superconducting MaterialEngineeringJosephson JunctionsSuperconductivityQuantum MaterialsHigh Tc SuperconductorsSuperconducting DevicesElectronic CircuitElectrical EngineeringHigh-tc SuperconductivityReduced InductancePhysicsGround PlaneDigital Circuit ApplicationsCobalt-doped Ybco BarrierMicroelectronicsHigh-temperature SuperconductivityApplied PhysicsQuantum DevicesQuantum Superconductivity
We have demonstrated a multilayer high-Tc junction process capable of fabricating small-scale digital circuits. The process uses superconductor/normal–metal/superconductor YBa2Cu3Ox (YBCO) edge junctions with a cobalt-doped YBCO barrier and an integrated YBCO ground plane. We have measured spreads in the junctions’ critical currents as low as 12% (1σ) both on and off the ground plane. The proper functioning of the ground plane was verified by measuring the reduced inductance of superconducting quantum interference devices (SQUIDs) on the ground plane compared to identical SQUIDs off the ground plane. At a temperature of 70 K, the inductance on the ground plane is as low as 1.2 pH/⧠. The inferred YBCO penetration depth is 250 nm at 70 K and 280 nm at 77 K.
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