Abstract: SQUIDs may detect local magnetic fields. SQUIDS of varying sizes, and hence sensitivities may detect different magnitudes of magnetic fields. SQUIDs may be oriented to detect magnetic fields in a variety of orientations, for example along an orthogonal reference frame of a chip or wafer. The SQUIDS may be formed or carried on the same chip or wafer as a superconducting processor (e.g., a superconducting quantum processor). Measurement of magnetic fields may permit compensation, for example allowing tuning of a compensation field via a compensation coil and/or a heater to warm select portions of a system. A SQIF may be implemented as a SQUID employing an unconventional grating structure. Successful fabrication of an operable SQIF may be facilitated by incorporating multiple Josephson junctions in series in each arm of the unconventional grating structure.

Abstract: A novel Josephson junction and a novel Josephson junction device are provided which eliminates the need to form an insulating barrier layer. The Josephson junction (1) comprises a superconductor layer (2) and a ferromagnetic layer (3) formed on a middle part (2C) of the superconductor layer (2). The ferromagnetic layer (3) may consist of an electrically conductive or insulating ferromagnetic layer, and may be an electrically conductive ferromagnetic layer formed via an insulating layer. With the superconductor layer (2) formed of a high temperature superconductor, a Josephson junction (1) is provided having large IcRN product. The Josephson junction (1) can be used as a junction for a variety of Josephson devices.

Abstract: The present invention provides a superconducting device including a substrate, a first superconducting pattern formed on the substrate, an insulating pattern formed on the first superconducting pattern, and a second superconducting pattern formed at the uppermost level in the multilayered superconducting pattern. A barrier layer of a Josephson junction is formed on the lower side of, or within the second superconducting pattern. The second superconducting pattern constitutes a circuit element on the insulating pattern.

Abstract: A solid state dc-SQUID includes a superconducting loop containing a plurality of Josephson junctions, wherein an intrinsic phase shift is accumulated through the loop. In an embodiment of the invention, the current-phase response of the dc-SQUID sits in a linear regime where directional sensitivity to flux through the loop occurs. Changes in the flux passing through the superconducting loop stimulates current which can be quantified, thus providing a means of measuring the magnetic field. Given the linear and directional response regime of the embodied device, an inherent current to phase sensitivity is achieved that would otherwise be unobtainable in common dc-SQUID devices without extrinsic intervention.

Abstract: A radiation detecting device including a superconducting tunnel junction having a three-layer structure formed by depositing a lower electrode, a tunnel barrier layer, and an upper electrode in sequence. The upper electrode, the tunnel barrier layer and lower electrode have substantially aligned side walls around substantially their entire perimeters such that a cross-section of the three-layer structure along a path perpendicular to a direction of the deposition is substantially constant in shape and size along the direction of the deposition and such that no portion of the lower electrode or the upper electrode extends beyond the tunnel barrier layer. At least one of the upper electrode and the lower electrode is made of superconducting material.

Abstract: A process for fabricating the Josephson junction includes the steps of preparing a substrate, forming a first superconducting layer, forming a second superconducting layer transversely on the first layer with an insulating layer interposed therebetween wherein the insulating layer is an oxide or nitride of the superconducting material, and injecting ion beams into the insulating layer so as to form low oxygen- or nitrogen-concentrated area linking the first and second layers.

Abstract: A DC SQUID has a first washer coil for forming a superconducting ring, Josephson junctions and a dampening resistor coupled to both ends of the first washer coil, and a shunting resistor connected in parallel to the Josephson junctions. An input coil is magnetically coupled with the first washer coil, and a first modulation coil is also magnetically coupled with the first washer coil. A ground plane comprising a superconducting film is disposed to cover an area of the Josephson junctions without covering the first washer coil for shielding the Josephson junctions from a magnetic noise. The ground plane prevents a magnetic flux trap from occurring, thus enabling stable operation of the DC SQUID. A washer cover comprising a superconducting film is disposed to cover only a slit portion of the first washer coil to prevent leakage of a magnetic field from the slit portion. The ground plane and the washer cover are simultaneously formed in a same layer of the DC SQUID.

Abstract: A Josephson device comprises a first electrode layer of a superconducting material and containing Nb therein as a constituent element, an overlayer of a nitride of a refractory metal element provided on the first electrode layer, a barrier layer of an insulating compound that contains the metal element as a constituent element and acting as a barrier of a Josephson junction, the barrier layer being provided on the overlayer, and a second electrode layer of a superconducting material and containing Nb therein as a constituent element, the second electrode layer being provided on the barrier layer.

Abstract: A method of fabricating a superconducting quantum interference device (DC-SQUID) constructed from short weak links with untrafine wires. The method comprises the following steps: successive forming a niobium nitride film and a silicon nitride film on a substrate; oblique etching of the niobium nitride film and said silicon nitride film with respect to the substrate by a reactive ion etching process using a mixture of oxygen and CF.sub.4 gases to form an olique edge; and successive forming a barrier thin film and a counterelectrode of niobium on the said edge. The short weak links wire fabricated by field evaporation technique. The counterelectrode material were field-evaporated and formed the conductive paths in the pinholes in the insulating thin film.

Abstract: A SQUID comprises a substrate, a washer of an oxide superconductor thin film formed on a principal surface of the substrate, a hole shaped a similar figure to the washer at the center of the washer, a slit formed between one side of the washer and the hole, and a Josephson junction which connects portions of the washer at the both sides of the slit across the slit. In the SQUID, the ratio of similarity of the washer to the hole ranges 100 to 2500.

Abstract: A process for producing a Josephson device is disclosed, wherein a Josephson junction is formed over a recess step by oblique deposition and a protective layer of conducting material or semiconducting material is formed on the Josephson junction. The actual thickness of the Josephson junction is controlled to be smaller due to the proximity effect.

Abstract: The disclosure relates to a Josephson junction formed by a non-superconducting barrier between two superconducting films of the (R) BaCuO (R=rare earth) group. In order to take advantage of the greater coherence length of superconductors along the CuO planes, i.e. perpendicularly to the long axis "c" of the crystal unit cell, the superconducting film is oriented so that the axis "c" is parallel to the plane of the junction. The device can be applied to Josephson junctions and to SQUIDs.

Abstract: A superconducting tunnel element, having a plurality of super conductors separated by barriers, the superconductors each comprising two physically separate but electrically connected superconducting layers and one insulated control layer. As a result, summation of the detection capacity or of the transmitting intensity becomes possible. Also, the simultaneous detection or transmission is permitted on arbitrary different frequencies or a summation of the signal intensity is possible in the case of SQUID-systems.

Abstract: A high current amplifier, three terminal device, comprising a Josephson tunnel junction and a Schottky diode is configured so that the Josephson junction and Schottky diode share a common base electrode which is made very thin. Electrons which cross the Schottky barrier are supplied to the Josephson junction to obtain the amplified output current.

Abstract: Technology for using a wiring of a superconductive material in semiconductor integrated circuit device. An isolation layer and/or a barrier layer are provided for preventing diffusion of harmful composition of the superconductive material for the semiconductor device. Control of a circuit can be made utilizing the characteristics of a superconductive material. Also, the characteristics of a superconductive material may be controlled. A method of forming a layer of superconductive material, well compatible with the widely used process of manufacturing integrated circuit devices, is also disclosed.

Abstract: One or more superconducting memory cells capable of storing binary values as the presence or absence of a persisting loop current in their superconducting memory loops are connected in series by a circuit current line. This arrangement is provided with a set gate which switches to the voltage state and outputs circuit current from its output terminal to one end of the circuit current line when write command current is supplied to its control terminal and is further provided with a sense gate whose control terminal is series coupled though a capacitance element with the same one end of the circuit current line and whose ground side terminal is connected with the other end of the circuit control line thereby forming through the sense gate a read-out loop for receiving as differential current persisting loop current selectively discharged from the memory loop. The differential current causes the sense gate to switch itself to the voltage state and output a sense current.

Abstract: A superconducting variable phase shifter providing improved performance in the microwave and millimeter wave frequency ranges. The superconducting variable phase shifter includes a transmission line and an array of superconducting quantum interference devices (SQUID's) connected in parallel with and distributed along the length of the transmission line. A DC control current I.sub.DC varies the inductance of the individual SQUID's and thereby the distributed inductance of the transmission line, thus controlling the propagation speed, or phase shift, of signals carried by the transmission line. The superconducting variable phase shifter provides a continuously variable time delay or phase shift over a wide signal bandwidth and over a wide range of frequencies, with an insertion loss of less than 1 dB. The phase shifter requires less than a milliwatt of power and, if one or more of the Josephson junctions fails, the whole device remains operational, since the SQUID's are connected in parallel.

Abstract: A superconducting weak link device includes a plurality of interconnected small superconducting regions and a plurality of conductive bridges which connect adjacent the small superconducting regions in which the length of the bridges is in the range from 1 to 5.31 times the coherence length.

Abstract: A high T.sub.c oxide superconductive switching device [10] formed on a substantially planar substrate [18] includes a base electrode [12] comprised of a layer or film of anisotropic superconducting material. The layer has a first crystalline axis [c] along which a magnitude of an energy gap of the material is less than an energy gap of the material along other crystalline axes. The superconductive switching device further includes at least one injector electrode [14] forming a planar [16] or an edge tunneling junction with the base electrode for injecting, under the influence of a bias potential eV, quasiparticles into the base electrode. The first crystalline axis is aligned in a predetermined manner with the tunneling junction for optimizing a quasiparticle injection efficiency of the tunneling junction.

Abstract: A field effect type Josephson transistor in which a source electrode and a drain electrode are provided with a gap therebetween, a tunnel film is provided in the gap between the source electrode and drain electrode, and a gate electrode for field-controlling the tunnel current through the tunnel film is provided. The transistor of such structure is suitable for mass-production and is utilized in manufacture of integrated circuits.

Abstract: A device comprising semiconductor elements and conductor tracks of an oxidic superconductive material, electrically conductive connections being established between the semiconductor elements and the conductor tracks, is provided with an electrically conductive antidiffusion layer between the semiconductor elements and the conductor tracks. The antidiffusion layer consists of an amorphous alloy of two transition metals, which alloy has a crystallization temperature of at least 900 K. The amorphous alloy has the composition A.sub.x B.sub.1-x, wherein A is selected from Ti, Zr, Hf, Nb and Ta, wherein B is selected from Ir, Pd and Pt, and wherein x has a value from 0.4 to 0.8.

Abstract: A Josephson device, comprising a junction formed by forming the first layer-shaped oxide superconductor thin film including a plurality of Cu-O layers on a substrate, a barrier layer thereon and the second layer-shaped oxide superconductor thin film on the barrier layer. The Josephson device according to the present invention is manufactured by forming the first layer-shaped oxide superconductor thin film on a substrate, forming a barrier layer in the same vacuum chamber, defining patterns to said barrier layer and said first layer-shaped oxide superconductor thin film, forming an interlayer insulating film on said barrier layer, removing said interlayer insulating film in a region serving as a junction, effecting exposure to oxygen plasma, forming the second layer-shaped oxide superconductor thin film in contact with a part of the surface of said barrier layer and defining patterns to said second layer-shaped oxide superconductor thin film.

Abstract: Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions.

Abstract: A Josephson junction type radiation energy analyzer comprising: a tunnel junction comprising a triple layer of superconductor-insulator-superconductor; and a metal layer which is provided in contact with one of the superconductors of the tunnel junction and to which radiation is incident.