Abstract:
A Josephson junction device is disclosed having a substrate upon which are located overlying and underlying high critical temperature crystalline oxide superconductive layers separated by an interposed impedance controlling layer. The underlying superconductive layer is limited to a selected area of the substrate while the overlying and interposed layers overlie only a portion of the underlying superconductive layer. Nonsuperconducting oxide layer portions laterally abut the superconductive and interposed layers. A first electrical conductor is attached to the underlying superconductive layer at a location free of overlying oxide layers, and a second electrical conductor contacts the overlying superconductive layer and extends laterally over the adjacent laterally abutting nonsuperconductive layer portion. A process is disclosed for preparing the Josephson junction device in which a Josephson junction layer sequence is deposited on a substrate, a portion of the Josephson junction layer sequence laterally abutting a selected area is converted to a nonsuperconducting form, within the selected area overlying layers are removed from the superconducting layer nearer the substrate, and an electrical conductor extends laterally from the superconducting layer farther removed from the substrate to the laterally abutting nonsuperconducting layer.