Abstract: A physical configuration for a parallel multi-junction superconducting quantum interference device that can be used for a variety of applications involving the detection of magnetic flux, including applications where it is desired to measure the absolute magnitude of the flux. The device of this invention features a novel geometry for a multi-junction interference device which significantly enhances the flux-to-voltage transfer function, thereby yielding a significant improvement in the device sensitivity in its use in a magnetometer, gradiometer, or other applications.

Abstract: A Josephson break junction device suitable for highly sensitive electronic detecting systems. A superconductor film such as YBa.sub.2 Cu.sub.3 O.sub.7 is deposited on a substrate such as a simple-crystal MgO. The film is fractured across a narrow strip by at least one indentation in the substrate juxtaposed from the strip to form a break junction. A transducer is affixed to the substrate for applying a bending movement to the substrate to regulate the distance across the gap formed at the fracture to produce a Josephson turned junction effect. Alternatively, or in addition to the transducer, a bridge of a novel metal is applied across the gap to produce a weak-link junction.

Abstract: A superconducting transistor is provided with a base layer made of a normal conductor metal, an emitter layer made of a superconductor for injecting hot electrons to the base layer, a collector layer made of a superconductor for trapping electrons from the base layer, a first tunnel barrier layer made of an insulator and provided between the base layer and the emitter layer, and a second tunnel barrier layer made of an insulator and provided between the base layer and the collector layer.

Abstract: A process for preparing a thin film of oxide superconductor on a single crystal substrate of semiconductor by RF sputtering. At first, an under-layer of an oxide having a thickness of 50 to 200 .ANG. is deposited on the single crystal substrate of semiconductor at a substrate temperature of lower than 500.degree. C., and secondly an upper-layer of superconducting oxide material is deposited on said under-layer at a substrate temperature of higher than 600.degree. C.

Abstract: A method for manufacturing a high Tc superconducting circuit elements is disclosed, which comprises the steps of preparing a single crystal conductive substrate of Sr.sub.2 RuO.sub.4 by a floating zone melting process; epitaxially growing on the (001)-surface of the Sr.sub.2 RuO.sub.4 substrate a high Tc copper oxide-based superconducting film with a thickness of 1 to 1000 nm; depositing metal pads onto said superconducting film to form electrical contacts; and applying a metal pad to the surface of the substrate to form an electrical contact.

Abstract: A tunable high-frequency device using a superconductive thin layer with a thickness smaller than the thickness of penetration of a magnetic field is positioned on a dielectric layer. Also included is a means for varying the density of the Cooper pairs of the superconductive thin layer.

Abstract: A process for etching with a scanning tunneling microscope on both a single crystal and a thin film of high temperature superconductor is disclosed.

Abstract: Epitaxial heterojunctions formed between high temperature superconductors and metallic or semiconducting oxide barrier layers are provided. Metallic perovskites such as LaTiO.sub.3, CaVO.sub.3, and SrVO.sub.3 are grown on electron-type high temperature superconductors such as Nd.sub.1.85 Ce.sub.0.15 CuO.sub.4-x. Alternatively, transition metal bronzes of the form A.sub.x MO.sub.3 are epitaxially grown on electron-type high temperature superconductors. Also, semiconducting oxides of perovskite-related crystal structures such as WO.sub.3 are grown on either hole-type or electron-type high temperature superconductors.

Abstract: A reflector has a body of a ceramic oxide superconductive material whose surface is treated to be diffusively reflective and is coated with diamond-like carbon or magnesium fluoride.

Abstract: An epitaxial structure comprising a silicon containing substrate and a high T.sub.c copper-oxide-based superconducting layer, which may include an intermediate layer between the silicon substrate and the superconductor layer. Epitaxial deposition is accomplished by depositing a superconductor on a (001) surface of silicon in a manner in which the unit cell of the superconductor layer has two out of three of its crystallographic axes rotated 45 degrees with respect to the corresponding axes of the silicon unit cell, the remaining axis of the superconductor unit cell being normal to the Si (001) surface.

Abstract: Improvement in a process for fabricating a superconducting junction by depositing successively a first oxide superconductor thin layer, a non-superconducting intermediate thin film layer and a second oxide superconductor thin film layer on a substrate in this order.In the invention, the non-superconducting intermediate thin film layer is composed of MgO and the substrate is preheated at 600.degree.-650.degree. C. for at least 5 minutes in the presence of O.sub.2, and is heated at a temperature between 200.degree. and 400.degree. C. during the non-superconducting intermediate thin film layer is deposited.

Abstract: An electron device comprises a first dielectric layer (103) having a first thickness determined to allow the tunneling of carriers therethrough and a first dielectric constant, a second dielectric layer (104) provided in contact with the first dielectric layer, the second dielectric layer having a second thickness substantially larger than the first thickness and a second dielectric constant that is substantially larger than the first dielectric constant, a first electrode (101) provided on the first dielectric layer for injecting the carriers, and a second electrode (108) provided in contact with the second dielectric layer for controlling a flow of the carriers through the second dielectric layer in response to a control voltage supplied thereto.

Abstract: Thin protective polyimide layers are produced on ceramic or high temperature superconductors by applying polyimide solutions, polyamic acids or starting substances therefor to the superconductor surface and imidating or drying in an oxygen atmosphere.

Abstract: A superconducting electronic circuit device, useful when impedance matching is desired, especially suited to microwave frequencies, consisting of a thin dielectric layer with superconducting layers on both sides. A superconductor such as Yttrium Barium Copper Oxide (YBCO) is formed on a first substrate such as lanthanum aluminate. A protective layer like gold is deposited on the YBCO and a second carrier substrate is bonded to the protected YBCO. The first substrate is then thinned into a thin dielectric film and a second layer of superconductor is epitaxially grown thereon to create the desired circuits.

Abstract: A method is disclosed for fabricating grain boundary junction devices, which comprises preparing a crystalline substrate containing at least one grain boundary therein, epitaxially depositing a high Tc superconducting layer on the substrate, patterning the superconducting layer to leave at least two superconducting regions on either side of the grain boundary and making electrical contacts to the superconducting regions so that bias currents can be produced across the grain boundary.

Abstract: A magnetic memory cell including an information storage unit of a three-layer structure having two magnetic thin films and a non-magnetic thin film interposed between the two thin films, an X-direction conductor and a Y-direction conductor intersecting each other at a position of the information storage unit, and a sense conductor located at a side of the X-direction conductor opposite to the Y-direction conductor. The sense conductor is separated from the X-direction conductor and extending to overlap the X-direction conductor. The two magnetic thin films have an equal saturation magnetic flux amount and an uniaxial magnetic anisotropy in the film plane, but are different from each other in either one of a magnetic anisotropy and a coercive force. The X-direction conductor, the Y-direction conductor and the sense conductor are formed of a superconductor material, and the sense conductor has a Josephson junction (superconduction weak link) positioned above the information storage unit.

Abstract: A superconducting field effect device includes a substrate with an epitaxial superconducting film upon it and an insulating layer above a thinner region of the film which protects the film from the atmosphere and isolates it from a gate electrode which is on the insulating layer above a channel region of the thin film, and the epitaxial film has thicker regions suitable for contact to source and drain electrodes. Gate electrodes may be isolated from and oppose both sides of the superconducting thin regions so that enhanced modulation of a current in the thin region is provided.The invention provides high speed and high efficiency switches and modulators.

Abstract: A ceramic superconductor comprising a metal oxide substrate, a ceramic high temperature superconductive material, and a intermediate layer of a material having a cubic crystal structure, said layer situated between the substrate and the superconductive material is provided, and a structure for supporting a ceramic superconducting material is provided, said structure comprising a metal oxide substrate, and a layer situated over the surface of the substrate to substantially inhibit interdiffusion between the substrate and a ceramic superconducting material deposited upon said structure.

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 microelectronic component comprising a crossover is provided comprising a substrate, a first high T.sub.c superconductor thin film, a second insulating thin film comprising SrTiO.sub.3 ; and a third high T.sub.c superconducting film which has strips which crossover one or more areas of the first superconductor film. An insitu method for depositing all three films on a substrate is provided which does not require annealing steps. The photolithographic process is used to separately pattern the high T.sub.c superconductor thin films.

Abstract: A method for sensing an applied magnetic field uses a superconductor element with superconductive material as a sensor. The element is cooled to its superconducting state and current is supplied to the element. An applied magnetic field is applied to the superconducting material and an output from the superconductor element is fed to a feed back power source. In the feedback power source a comparison is made between an input voltage from the superconductive element and a reference voltage. Current is applied to a coil for applying a bias magnetic field to the superconductor element based on the comparison. With this method, the input voltage and the reference voltage are made as equal as possible. A superconductive device includes a coil for applying an AC power source and a coil for applying a DC power source.

Abstract: In a method of forming an oxide superconductor/semiconductor junction between an oxide superconductor and a semiconductor containing bismuth or thallium, an atomic layer of silver of no more than 3 atoms thickness is formed by vapor deposition of silver on the surface of the semiconductor, an atomic layer of bismuth or thallium of no more than 3 atoms thickness is formed by vapor deposition of bismuth or thallium on the silver layer, the double atomic layer consisting of silver and bismuth or of silver and thallium are heated to form a layer wherein the atoms of silver and bismuth or silver and thallium are arranged regularly on the surface of the semiconductor, and the oxide superconductor is formed to a specified thickness on the regularly arranged layer.

Abstract: An article of manufacture including a substrate, a patterned interlayer of a material selected from the group consisting of magnesium oxide, barium-titanium oxide or barium-zirconium oxide, the patterned interlayer material overcoated with a secondary interlayer material of yttria-stabilized zirconia or magnesium-aluminum oxide, upon the surface of the substrate whereby an intermediate article with an exposed surface of both the overcoated patterned interlayer and the substrate is formed, a coating of a buffer layer selected from the group consisting of cerium oxide, yttrium oxide, curium oxide, dysprosium oxide, erbium oxide, europium oxide, iron oxide, gadolinium oxide, holmium oxide, indium oxide, lanthanum oxide, manganese oxide, lutetium oxide, neodymium oxide, praseodymium oxide, plutonium oxide, samarium oxide, terbium oxide, thallium oxide, thulium oxide, yttrium oxide and ytterbium oxide over the entire exposed surface of the intermediate article, and, a ceramic superco nFIELD OF THE INVENTIONThe pre

Abstract: A laminated film comprising at least two thin films of single crystal LnBa.sub.2 Cu.sub.3 O.sub.7-x wherein Ln is Y or one of lanthanoids except Pr and Tb having the (001) plane in the direction parallel with the film surface and at least one continuous thin film of Y.sub.2 O.sub.3 which has a thickness of not larger than 100 .ANG. and the (001) plane in the direction parallel with the film surface and is interposed between a pair of said thin films of single crystal LnBa.sub.2 Cu.sub.3 O.sub.7-x, wherein the thin films of single crystal LnBa.sub.2 Cu.sub.3 O.sub.7-x has good superconductive properties.

Abstract: A method of forming a superconductor pattern in which at lest a pair of electrodes is formed on a substrate in spaced, facing relationship nd an oxide superconductor thin film having a unit lattice which assumes a laminar structure then is formed on the substrate, extending between and contacting the electrodes. The superconductor pattern obtained by this method suffers less degradation of the superconductor thin film, in comparison with that of patterns formed by the prior art methods, and the decrease of the critical current density as a function of increasing temperature is extremely small.

Abstract: The disclosed superconductive optoelectronic device stems from the inventor's important discovery of a phenomenon that the basic substance Cu.sub.2 O reveals photoconductivity below several temperatures T.sub.ps in steps thereof, T.sub.ps being comparable with a series of the critical temperatures of superconductivity T.sub.sc of relevant Cu-based superconductors, and such photoconductivity of the basic substance is in a conjugate relationship with the superconductivity of the above Cu-based superconductors. The device of the invention has a gate region made of the above basic substance Cu.sub.2 O and a source region and a drain region made of the above Cu-based superconductors, the source and drain regions connected to each other, so that electric current therebetween at a temperature below the step temperature T.sub.ps of the basic substance is switched and/or controlled by the incident light intensity illuminated to the gate region.

Abstract: A method of forming a superconducting circuit comprises the steps of preparing a ceramics body which is changed from a non-superconductive phase not superconducting at the working temperature into a superconducting phase superconducting at the working temperature by heat treatment and performing the heat treatment on a part of the ceramics body by applying a laser beam to the ceramics body to change the same into the superconductive phase, thereby to form a superconducting circuit consisting of the superconductive phase and the non-superconductive phase on the ceramics body.

Abstract: A cubic perovskite crystal structure is disclosed satisfying the unit cell formula:R.sub.0.33+z A.sub.0.67 C.sub.1-y O.sub.3-xwhereR, A and C represent rare earth, alkaline earth and copper atoms, respectively, capable of forming a superconductive R.sub.1 A.sub.2 C.sub.3 orthorhombic perovskite crystal structure;x is 0.67 to 1.0;y is up to 0.2; andz is up to 0.1.The crystal structure can be used to form superconductive superlattices and weak links for Josephson junction devices. The crystal structure can be produced by laser ablation deposition at a temperature below that required for the formation of a superconductive R.sub.1 A.sub.2 C.sub.3 orthorhombic perovskite crystal structure. The crystal structure can be used as a substrate for the subsequent deposition of an R.sub.1 A.sub.2 C.sub.3 orthorhombic perovskite crystal structure.

Abstract: Disclosed is a transistor or diode type Josephson effect device, at least two electrodes of which are made of superconductive material. If the Josephson effect is to be exerted in a semiconductor layer between the access electrodes, the distance between them should be smaller than the length of coherence, namely 10 to 1000 angstroms. According to the disclosure, the control channel between access electrodes is replaced by two channels perpendicular to the semiconductor layer, located between the two access electrodes and a layer of superconductive material placed between the substrate and the semiconductor layer. The disclosure can be applied to transistors, phototransistors and diodes with high switching speed.

Abstract: A superconducting device includes a superconducting channel consituted of an oxide superconductor thin film formed on a substrate, a superconductor source electrode and a superconductor drain electrode formed at opposite ends of the superconducting channel, so that a superconducting current can flow through the superconducting channel between the source electrode and the drain electrode. A gate electrode is located through an insulating layer on the superconducting channel so as to control the superconducting current flowing through the superconducting channel. The oxide superconductor thin film of the superconducting channel is formed of a c-axis oriented oxide superconductor crystal, and the oxide superconductor thin film of the superconductor source electrode and the superconductor drain electrode are formed of an a-axis oriented oxide superconductor crystal. The superconducting channel is continuous with the superconductor source electrode and the superconductor drain electrode.

Abstract: A superconducting device has a structure of superconductor - normal-conductor (semiconductor) - superconductor. The superconductors constituting the superconducting device are made of a super-conducting oxide material of K.sub.2 NiF.sub.4 type crystalline structure or perovskite type crystalline structure which contains at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Ra; at least one element selected from the group consisting of La, Y, Ce, Sc, Sm, Eu, Er, Gd, Ho, Yb, Nd, Pr, Lu and Tb; Cu; and O.

Abstract: A superconductor structure having a substrate, the substrate defining a surface. Applied to the surface of the substrate is a barrier layer. Applied to the barrier layer is a layer of superconductive material comprising copper and oxygen. The barrier layer serves to prevent the interaction of the superconductive material with the substrate, thus destroying the stoichiometry of the superconductive material and resulting in a loss or decrease in superconductivity. A protective layer is, optionally, applied to the layer of superconductive material.

Abstract: A method for fabricating an active device comprises the steps of injecting particles into a single crystal substrate of a semiconductor material at a predetermined depth from the surface, annealing the substrate that contains the particles to form an insulator layer within the substrate, generally in correspondence to the predetermined depth, the step of annealing including a step of forming a single crystal semiconductor layer of a semiconductor material identical in composition with the substrate, on the insulator layer that is formed by the annealing, starting a deposition of a layer of an oxide superconductor on the semiconductor layer, growing the oxide superconductor layer while maintaining an epitaxial relationship with respect to the substrate; and converting the semiconductor layer to an oxide layer simultaneously to the growth of the oxide superconductor layer.

Abstract: The structures for confining or guiding high frequency electromagnetic radiation have surfaces facing the radiation constructed of high temperature superconducting materials, that is, materials having critical temperatures greater than approximately 35.degree. K. The use of high temperature superconductors removes the constraint of the relatively low energy gaps of conventional, low temperature superconductors which precluded their use at higher frequencies. The high temperature superconductors also provide larger thermal margins and more effective cooling. Devices which will benefit from the structures of the invention include microwave cavities, millimeter-wave/far infrared cavities, gyrotron cavities, mode converters, accelerators and free electron lasers, and waveguides.

Abstract: A method for forming an insulating layer in an oxide high-temperature superconductor is described. The oxide high-temperature superconductor is exposed to radiation, whereby an interface showing superconducting characteristics and/or a weak link that is present at an interface in the said oxide high-temperature superconductor is transformed to a thin insulating layer.

Abstract: A method of forming a fine groove on a superconducting thin film. A superconducting oxide thin film is formed on a MgO substrate, and a damaged layer is formed thereon by irradiating the superconducting thin film with focused ion beams to such a degree that not sputter is generated and the crystalline structure of the superconducting thin film is disturbed. The damaged layer is then removed by treatment with a strong alkali such as KOH. Thus, a fine groove is effectively formed. By inserting an oxide layer between the substrate and the superconducting thin film, a Josephson junction device suitable for superconducting transistors is produced.

Abstract: In a dc SQUID element having two quasi-planar-type Josephson junction portions, as obtained by laminating a plurality of superconducting thin films on a substrate, a SQUID ring and a counter electrode on either of which quasi-planar-type Josephson junction portions are to be formed, are respectively formed at the lowermost layer and the uppermost layer, or at the uppermost layer and the lowermost layer, so that the value of critical current can be adjusted. The arrangement above-mentioned assures good flatness and film quality of a barrier layer interposed between the lower and upper electrodes of the quasi-planar-type Josephson junction portions.

Abstract: A superconducting pattern formed from a superconducting ceramic film is illustrated. The pattern is made in the form of a coil which is embedded in an insulating ceramic film. The insulating film is made of a ceramic material whose thermal expansion coefficient is approximately equal to that of the coil.

Abstract: A [100] oriented ZrO.sub.2 thin film is formed on selected regions of a [100] deposition surface of a silicon substrate, and a Y.sub.2 O.sub.3 thin film deposited on the ZrO.sub.2 thin film and exposed regions of the deposition surface of the silicon substrate. A Y-Ba-Cu type compound oxide superconducting thin is deposited on the Y.sub.2 O.sub.3 thin film. The Y-Ba-Cu type compound oxide superconducting thin film positioned above the ZrO.sub.2 thin film is crystal-grown in a [001] orientation, and the Y-Ba-Cu type compound oxide superconducting thin film is crystal-grown in a [110] orientation in the other region.

Abstract: A superconducting Josephson junction is created in high T.sub.c superconducting film, with a bridge connecting two superconducting banks, by subjecting the bridge to a tunneling electron current from a sharp electrode close to the bridge. The tunneling current alters the structure over atomic dimensions to create a weak link of length comparable to high T.sub.c coherence lengths so as to permit phase coherent Cooper pair current flow across the weak link.

Abstract: The present invention provides a process for producing a superconducting transistor on a surface of an insulating substrate. A pre-superconducting thin film contains a material that can be changed into a superconductor during subsequent processing but which is initially a non-superconductor. A thin film containing the material required by the pre-superconducting thin film is deposited in a preferred pattern on the pre-superconducting thin film. The assembly thus formed is heat treated to permit the material from the thin film to enter the pre-superconducting thin film, thereby forming superconducting regions in the pre-superconducting thin film in the preferred pattern. The superconducting regions form electrodes of the transistor.

Abstract: Since a superconducting quantum interference device (SQUID) using a high temperature superconductor operates at the liquid nitrogen temperature 77 K, which is higher than the liquid helium temperature 4.2 K, it is necessary that the value of signal voltages is at a level, which is sufficiently higher than the thermal noise level. The superconducting inductance L should be decreased with increasing current flowing through Josephson junctions in the SQUID. The superconducting inductance can be reduced by various methods such as reduction in the size of the aperture of the superconducting inductance, parallel connection of superconducting inductances, utilization of a superconducting ground plane, etc., in order to realize a SQUID, which can be use in a wide application field at the liquid nitrogen temperature 77 K.

Abstract: In a method of manufacturing a superconducting device which has a first thin film of oxide superconductor material formed on a substrate and a second thin film formed on the first thin film of oxide superconductor material, after the second thin film is deposited on the first thin film of oxide superconductor material, a multi-layer structure formed of the first and second thin films is patterned so that a side surface of the first thin film is exposed. In this condition, the whole of the substrate is heated in an O.sub.2 atmosphere or in an O.sub.3 atmosphere so that oxygen is entrapped into the first thin film of oxide superconductor material. Thereafter, the patterned multi-layer structure is preferably covered with a protection coating.

Abstract: A magnetometer is prepared by depositing three thin-film SQUID magnetic field detectors upon a substrate. Two of the detectors incorporate stripline SQUID detectors deposited at right angles to each other, to measure the orthogonal components of a magnetic field that lie in the plane of the substrate. The third detector uses a planar loop SQUID detector that measures the component of the magnetic field that is perpendicular to the substrate. The stripline SQUID detectors have thin-film base and counter electrodes separated by an insulating layer which is at least about 1 micrometer thick, and a pair of Josephson junctions extending between the electrodes through the insulating layer.

Abstract: An oxide-superconducting device comprises first and second electrodes of oxide-superconductor which are connected through a tunnel barrier layer. The oxide-superconductor is formed on a substrate having a recess, and it includes grain boundaries along the recess. The tunnel barrier layer is formed along the grain boundaries, and it is made of any material of an element F, Cl, Br, I, C, O, S, P or N, a mixture consisting of such elements, and a compound containing such an element, the material being introduced into the grain boundaries and/or lattice interstices near the grain boundaries.

Abstract: A method for generating repeatable and reproducible crystallographic grain-boundary junctions is provided by forming a film on a crystalline substrate which has intersecting faces. In a preferred embodiment, a single crystal substrate is etched by an anisotropic etchant to provide a "V"-groove in one face, and an epitaxial superconducting film is grown on the faces of the V-groove. In another preferred embodiment, a step is etched with an anisotropic etch, and an epitaxial superconducting film grown on the step. Grain-boundary junctions are formed at the points of intersection of the faces with each other, or with the faces and the surface of the substrate. The film may be patterned and etched in the area of the boundary junction to form useful devices.

Abstract: Disclosed here is a shaped article superconductor comprising platelets of superconducting oxide crystals which are normally anisotropic but in which said anisotropy is reduced by joining together the oxides superconductor crystallites with a normally conductive metal layer interposed therebetween. The separation distances of the platelets are, on the average, less than the coherence length of the normally conductive metal under conditions which render the oxide crystals superconductive.

Abstract: A method for manufacturing a superconductive multilayer circuit has a first thin film forming step for forming a thin film, which is composed of superconductive material or a similar material thereto, on a substrate, a first circuit layer forming step for forming a superconductive circuit by discharging a specific component from a predetermined part of the thin film or implanting the component in the thin film, a second thin film forming step for forming a thin film, which is composed of a superconducting material or the simulant thereto, on the first circuit layer, and a second circuit layer forming step for forming a superconductive circuit by removing a specific component from a predetermined part of the thin film or implanting the component in the thin film.

Abstract: A transistor structure which utilizes the Josephson effect and/or tunneling effect. The Josephson transistors of the invention are composed of superconductive films and tunneling films and work at a high speed with a low energy consumption. They are suitable for the construction of integrated circuits, especially digital circuits.