Josephson Junction Present Patents (Class 505/702)
  • Patent number: 8200304
    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.
    Type: Grant
    Filed: July 20, 2007
    Date of Patent: June 12, 2012
    Assignee: Japan Science and Technology Agency
    Inventors: Atsutaka Maeda, Espinoza Luis Beltran Gomez
  • Patent number: 8055318
    Abstract: A new family of superconducting materials with critical temperature up to 55 K have recently been discovered, comprising a crystal structure with atomic layers of iron and arsenic alternating with atomic layers of rare-earth oxide or alkaline earth. The present invention identifies structures for integrated circuit elements (including Josephson junctions) in these and related materials. These superconducting circuit elements will operate at a higher temperature than low-temperature superconductors such as niobium, and may be easier to manufacture than prior-art high-temperature superconductors based on copper-oxides.
    Type: Grant
    Filed: April 22, 2009
    Date of Patent: November 8, 2011
    Assignee: Hypres, Inc.
    Inventor: Alan M. Kadin
  • Patent number: 8032196
    Abstract: A Josephson device includes a first superconducting electrode layer, a barrier layer and a second superconducting electrode layer that are successively stacked. The first and second superconducting electrode layers are made of an oxide superconductor material having (RE)1(AE)2Cu3Oy as a main component, where an element RE is at least one element selected from a group consisting of Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, and an element AE is at least one element selected from a group consisting of Ba, Sr and Ca. The barrier layer is made of a material that includes the element RE, the element AE, Cu and oxygen, where in cations within the material forming the barrier layer, a Cu content is in a range of 35 At. % to 55 At. % and an RE content is in a range of 12 At. % to 30 At. %, and the barrier layer has a composition different from compositions of the first and second superconducting electrode layers.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: October 4, 2011
    Assignees: Chugoku Electric Power Co., Inc., International Superconductivity Technology Center, The Juridical Foundation
    Inventors: Hironori Wakana, Seiji Adachi, Koji Tsubone, Keiichi Tanabe
  • Patent number: 7979101
    Abstract: It is possible to improve the negative resistance characteristic that can be expected when an SNS (superconductor-normal conductor-superconductor) structure is used as a structure unit for series connection. On the top of a first superconducting electrode, a second superconducting electrode is superimposed so as to sandwich an insulation film between the first and second superconducting electrodes, with parts of cross sections of the second superconducting electrode and insulation film placed on the top. A normal superconducting line electrically connects the first and second superconducting electrodes passing along the cross section of the insulation film, thereby constituting a structure unit having a single weak link. A plurality of such structure units connected in series are prepared. At the both ends of the series the first or second superconducting electrode is an element connected to a leading line.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: July 12, 2011
    Assignee: National Institute of Information and Communications Technology, Incorporated Administrative Agency
    Inventors: Toshiaki Matsui, Hiroshi Ohta, Akira Kawakami
  • Patent number: 7816303
    Abstract: A laminated superconductor wire includes a superconductor wire assembly, which includes a first superconductor insert comprising a first high temperature superconductor layer overlaying a first substrate and a second superconductor insert comprising a second high temperature superconductor layer overlaying a second substrate. The first and second superconductor inserts are joined together at their respective substrates. An electrically conductive structure substantially surrounds the superconductor wire assembly.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: October 19, 2010
    Assignee: American Superconductor Corporation
    Inventors: Cornelis Leo Hans Thieme, Alexis P. Malozemoff, Martin W. Rupich, Urs-Detlev Schoop, Elliott D. Thompson, Darren Verebelyi
  • Patent number: 6926921
    Abstract: One aspect of this disclosure relates to a method of building a superconductor device on a substrate, comprising depositing an imprint layer on at least a portion of the substrate. The imprint layer is imprinted to provide an imprinted portion of the imprint layer and a non-imprinted portion of the imprint layer. A superconductor layer is deposited on at least a portion of the imprinted portion of the imprint layer.
    Type: Grant
    Filed: May 5, 2003
    Date of Patent: August 9, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: James Stasiak, Pavel Kornilovich
  • Publication number: 20030207766
    Abstract: A superconducting quantum-bit device based on Josephson junction has a charge as a first principal degree of freedom assigned to writing and a phase as a second principal degree of freedom assigned to reading. The device comprises a Cooper-pair box comprising first and second Josephson junctions defining a charge island of the Cooper-pair box closing up onto a superconducting loop. A read circuit comprises a read Josephson junction JL inserted into the superconducting loop and having a Josephson energy Ej at least 50 times greater than the Josephson energy of each of the first and second Josephson junctions.
    Type: Application
    Filed: September 16, 2002
    Publication date: November 6, 2003
    Inventors: Daniel Esteve, Denis Vion, Michel Devoret, Cristian Urbina, Philippe Joyez, Hughes Pothier, Pierre-Francois Orfila, Abdelhahim Aassime, Audrey Cottet
  • Patent number: 6515788
    Abstract: A method and apparatus for modulating light, wherein a light source provides light of a certain wavelength to be modulated by a layer of superconducting material which forms part of a specifically configured plate assembly. The superconducting layer is placed in the optical path of the light source. Further the superconducting layer is switched between a partially transparent non-superconducting state and a substantially non-transparent superconducting state by a modulation circuit. The resulting optical pulses transmitted through the superconducting layer are converted from the original wavelength to a lower wavelength by a frequency converting device.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: February 4, 2003
    Inventor: Kenneth A. Puzey
  • Patent number: 6388268
    Abstract: A semiconducting yttrium-barium-copper-oxygen(YBCO) device which locally converts a semiconducting YBCO film to a nonconducting YBCO film by a conductive atomic force microscope (AFM), a superconducting YBCO device which locally converts a superconducting YBCO film to nonsuperconducting YBCO by an AFM, and manufacturing methods thereof are provided. According to a method of manufacturing a semiconducting YBCO device or a superconducting YBCO device locally converted by an AFM tip, a voltage is applied to the local region of a semiconducting YBCO channel or a superconducting YBCO channel by an AFM tip. This can produce a nonconducting YBCO region or nonsuperconducting YBCO region to thereby manufacture a tunnel junction easily without any patterning process by microfabrication including photolithography and dry/wet etching.
    Type: Grant
    Filed: September 26, 2000
    Date of Patent: May 14, 2002
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Byong-man Kim, Insang Song
  • Patent number: 6372368
    Abstract: An oxide superconducting element is formed on a substrate 10 by a layered structure 30 formed of oxide superconducting thin-film and a non-superconducting thin-film layers. The element is a superconducting regular current interval voltage step element. The current-voltage characteristic curve in a magnetic field has a voltage step being generated at regular bias current intervals. The layered structure 30 is formed by depositing alternately M′Ba2Cu3O7 (M′ is one or a combination of more than two elements of Nd, Sm and Eu) and M″Ba2Cu3O7 thin-films (M″ is either Pr or Sc, or a combination of the two elements).
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: April 16, 2002
    Assignee: International Superconductivity Technology Center
    Inventors: Gustavo Adolfo Alvarez, Youichi Enomoto
  • Patent number: 6337149
    Abstract: A lanthanum aluminate (LaAlO3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also be used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: January 8, 2002
    Assignee: TRW Inc.
    Inventors: Randy Wayne Simon, Christine Elizabeth Platt, Alfred Euinam Lee, Gregory Steven Lee
  • Patent number: 6324413
    Abstract: A lanthanum aluminate (LaAlO3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: November 27, 2001
    Assignee: TRW Inc.
    Inventors: Randy Wayne Simon, Christine Elizabeth Platt, Alfred Euinam Lee, Gregory Steven Lee
  • Patent number: 6305069
    Abstract: Provided are an oxide superconducting wire which maintains a high critical current density and has a small current drift with small ac loss when the same carries an alternating current and a method of preparing the same, and a cable conductor which is formed by assembling such oxide superconducting wires. The oxide superconducting wire is a flat-molded stranded wire which is formed by twisting a plurality of metal-coated strands consisting of an oxide superconductor, and is characterized in that the flat-molded stranded wire has a rectangular sectional shape, and a section of each strand forming the flat-molded stranded wire has an aspect ratio (W1/T1) of at least 2. The method of preparing this oxide superconducting wire comprises the steps of preparing a stranded wire by twisting a plurality of strands, each of which is formed by metal-coating an oxide superconductor or raw material powder therefor, flat-molding the prepared stranded wire, and repeating rolling and a heat treatment of at least 800° C.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: October 23, 2001
    Assignee: Sumitomo Electric Industries, Inc.
    Inventors: Jun Fujikami, Nobuhiro Saga, Kazuya Ohmatsu, Kenichi Sato
  • Patent number: 6226538
    Abstract: This magnetic sensor comprises a flux transformer 2 having a superconducting thin film 2f formed on a sapphire substrate 2s, and a SQUID 1 disposed on the flux transformer 2 opposite thereto. In this magnetic sensor, since the sapphire substrate 2s, which can be obtained in a large size, is used for the flux transformer 2, even when the SQUID 1 is made smaller, the magnetic flux introduced from the flux transformer 2 into the SQUID 1 can be enhanced so as to increase the effective magnetic flux capturing area, whereby the detecting performance is improved, while the manufacturing cost can be reduced due to the smaller size of the SQUID 1.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: May 1, 2001
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hirokazu Kugai, Tatsuoki Nagaishi, Hideo Itozaki
  • Patent number: 6188919
    Abstract: A SNS Josephson junction (10) is provided for use in a superconducting integrated circuit. The SNS junction (10) includes a first high temperature superconducting (HTS) layer (14) deposited and patterned on a substrate (18), such that the first HTS layer (14) is selectively removed to expose a top surface of the substrate (18) as well as to form an angular side surface (22) on the first HTS layer (14) adjacent to the exposed top surface of the substrate (18). Ion implantation is used to form a junction region (12) having non-superconducting properties along the angular side surface (22) of the first HTS layer (14). A second HTS layer (16) is then deposited and patterned over at least a portion of the first HTS layer (14) and the exposed top surface of the substrate (18), thereby forming a SNS Josephson junction.
    Type: Grant
    Filed: May 19, 1999
    Date of Patent: February 13, 2001
    Assignee: TRW Inc.
    Inventors: John R. LaGraff, James M. Murduck, Hugo W-K. Chan
  • Patent number: 6066600
    Abstract: A high temperature superconductor junction and a method of forming the junction are disclosed. The junction 40 comprises a first high-T.sub.c superconductive layer (first base electrode layer) 46 on a substrate 42 and a dielectric layer 48 on the first high-T.sub.c superconductive layer. The dielectric layer and the first high-T.sub.c superconductive layer define a ramp edge 50. A trilayer SNS structure 52 is disposed on the ramp edge to form an SSNS junction. The SNS structure comprises a second high-T.sub.c superconductive layer (second base electrode layer) 54 directly on the first high-T.sub.c superconductive layer, a normal barrier layer 56 on the second high-T.sub.c superconductive layer, and a third high-T.sub.c superconductive layer 58 (counterelectrode) on the barrier layer. The ramp edge is typically formed by photoresist masking and ion-milling. A plasma etch step can be performed in-situ to remove the photoresist layer 62 following formation of the ramp edge.
    Type: Grant
    Filed: January 22, 1998
    Date of Patent: May 23, 2000
    Assignee: TRW Inc.
    Inventor: Hugo W. Chan
  • Patent number: 6011981
    Abstract: An oxide superconducting multilayered thin film structure having a laminated layer structure of oxide superconductor thin film layers and non-superconductor thin film layers constituted by a combination of material groups for making strain free interfaces among both thin film layers. For example, an oxide superconductor multilayered film constituted by a laminated layer structure where thin films of an oxide superconductor represented by the chemical formula of M'Ba.sub.2 Cu.sub.3 O.sub.7-.delta. (M'; a rare earth element of Nd, Sm, Eu or the like or an alloy of these, .delta.; oxygen depletion amount) and thin films of an oxide represented by the chemical formula of M*Ba.sub.2 Cu.sub.3 O.sub.7-.delta. (M*; an element of Pr, Sc or the like or an alloy of these, .delta.; oxygen depletion amount) are alternately stacked. The oxide thin films are thin films fabricated by a pulsed laser deposition process or a sputtering process. A Josephson device can be provided by using the multilayered film.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: January 4, 2000
    Assignee: International Superconductivity Technology Center
    Inventors: Gustavo Alvarez, Furen Wang, Jian-Guo Wen, Naoki Koshizuka, Youichi Enomoto, Tadashi Utagawa, Shoji Tanaka
  • Patent number: 6004907
    Abstract: The present invention forms a superconducting junction using a cubic YBa.sub.2 Cu.sub.3 Ox thin film as a barrier layer. The present invention forms a first YBCO superconducting thin film, a SrTiO.sub.3 insulating layer thin film on the substrate, etches a side of them in the form of inclination, subsequently integrates a non-superconducting cubic YBCO barrier thin film, a second YBCO superconducting thin film, a SrTiO.sub.3 protecting layer thin film in series on the whole surface of the substrate, etches an opposite side of the etched part of the SrTiO.sub.3 insulating layer thin film in the form of inclination, fabricates a superconducting junction by forming a metal electrode to said aperture after forming apertures which expose said first YBCO superconducting thin film, the second YBCO superconducting thin film, fabricates a superconducting junction upon forming the metallic electrode to the apertures, and deposits a cubic YBa.sub.2 Cu.sub.3 Ox barrier thin film at a temperature of 600-650.degree. C.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: December 21, 1999
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Jeong Dae Suh, Gun Yong Sung
  • Patent number: 5955743
    Abstract: The invention relates to a superconductive tunnel element comprising superconductors, barriers and insulators, which tunnel element has the following layer structure: superconductor (S1), insulator (I), superconductor (S2), barrier (B), superconductor (S3), insulator (I) and superconductor (S4).
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: September 21, 1999
    Inventor: Hehrwart Schroeder
  • Patent number: 5945383
    Abstract: A method of producing a high temperature superconductor Josephson element and an improved SNS weak link barrier element is provided. A YBaCuO superconducting electrode film is deposited on a substrate at a temperature of approximately 800.degree. C. A weak link barrier layer of a nonsuperconducting film of N--YBaCuO is deposited over the electrode at a temperature range of 520.degree. C. to 540.degree. C. at a lower deposition rate. Subsequently, a superconducting counter-electrode film layer of YBaCuO is deposited over the weak link barrier layer at approximately 800.degree. C. The weak link barrier layer has a thickness of approximately 50 .ANG. and the SNS element can be constructed to provide an edge geometry junction.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: August 31, 1999
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Brian D. Hunt
  • Patent number: 5916848
    Abstract: An edge junction 10 with reduced parasitic inductance. The edge junction 10 has a laminar structure 22 including: a substrate 14; a first superconductive layer 12 deposited on a substrate 14; a first dielectric layer 16 deposited on the first superconductive layer 12; a second superconductive layer 18 deposited on the first dielectric layer 16; and a second dielectric layer 20 deposited on the second superconductive layer 18. The first and second superconductive layers 12 and 18 and the first and second dielectric layers 16 and 20 form a first laminar structure 22 having a planar segment 24 and a self-aligned ramp segment 26, the ramp segment 26 having a constantly-decreasing thickness and being connected to the planar segment 24 at an angle .theta. thereto.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: June 29, 1999
    Assignee: TRW Inc.
    Inventor: Dale J. Durand
  • Patent number: 5906963
    Abstract: A lanthanum aluminate (LaAlO.sub.3) substrate on which thin films of layered perovskite copper oxide superconductors are formed. Lanthanum aluminate, with a pseudo-cubic perovskite crystal structure, has a crystal structure and lattice constant that closely match the crystal structures and lattice constants of the layered perovskite superconductors. Therefore, it promotes epitaxial film growth of the superconductors, with the crystals being oriented in the proper direction for good superconductive electrical properties, such as a high critical current density. In addition, LaAlO.sub.3 has good high frequency properties, such as a low loss tangent and low dielectric constant at superconductive temperatures. Finally, lanthanum aluminate does not significantly interact with the superconductors. Lanthanum aluminate can also used to form thin insulating films between the superconductor layers, which allows for the fabrication of a wide variety of superconductor circuit elements.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: May 25, 1999
    Assignee: TRW Inc.
    Inventors: Randy Wayne Simon, Christine Elizabeth Platt, Alfred Euinam Lee, Gregory Steven Lee
  • Patent number: 5891828
    Abstract: PrBa.sub.2 Cu.sub.3 O.sub.Y exhibiting superconductivity is provided by a method including the steps of preparing a solvent consisting of a mixture of praseodymium oxide, at least one of barium oxide and barium carbonate, and copper oxide at a mixing ratio of between 1:3:5 and 1:8:20, disposing the solvent between a feed rod of PrBa.sub.2 Cu.sub.3 O.sub.7 formed to a high density and a seed crystal, heating the solvent to a temperature of 880.degree.-980.degree. C. in an atmosphere of an inert gas of at least one of argon and nitrogen mixed with 0.01-2% oxygen to form a floating solvent zone, moving the floating solvent zone toward the feed rod at 0.1-1.0 mm/hr under a temperature gradient at the solid-liquid interface of 25.degree.-35.degree. C./mm to precipitate single crystal on the seed crystal, and heat-treating the single crystal obtained in an atmosphere containing not less than 15% oxygen. Another aspect of the invention provides a superconducting device including the superconducting PrBa.sub.2 Cu.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: April 6, 1999
    Assignee: Agency of Industrial Science & Technology, Ministry of International Trade & Industry
    Inventors: Kunihiko Oka, Zhigang Zou, Toshimitsu Ito, Hiroshi Akoh
  • Patent number: 5883051
    Abstract: A superconducting Josephson junction element including a first, a-axis oriented, superconductive metal oxide crystal grain having a first area of a {001} plane, and a second, c-axis oriented, superconductive metal oxide crystal grain having a second area of a {110} plane, wherein the first and second crystal grains are in contact with each other at the first and second areas to form a grain boundary therebetween.
    Type: Grant
    Filed: October 22, 1996
    Date of Patent: March 16, 1999
    Assignee: International Superconductivity Technology Center
    Inventors: Yoshihiro Ishimaru, Jian-Guo Wen, Kunihiko Hayashi, Youichi Enomoto, Naoki Koshizuka, Shoji Tanaka
  • Patent number: 5880069
    Abstract: A desired pattern is formed on a non-superconducting oxide film after the non-superconducting oxide film has been formed on a magnesia substrate. A superconducting oxide film is formed over the exposed parts of the substrate and the non-superconducting oxide film. The epitaxial orientation of the superconducting oxide film section on the non-superconducting oxide film is different from that of the superconducting oxide film section on the substrate. A tilt-boundary junction is produced at a boundary between the superconducting film sections which are different in epitaxial orientation from each other. Thus, a Josephson junction having a desired pattern can be obtained.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: March 9, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masao Nakao, Hiroaki Furukawa, Ryohkan Yuasa, Shuji Fujiwara
  • Patent number: 5877122
    Abstract: An oxide superconductor element, produced by forming a damaged region on a substrate surface by the Ga.sup.+ focusing ion beam method and then depositing an oxide superconductor thin-film over it, is characterized in that a NdBa.sub.2 Cu.sub.3 O.sub.7-y (0.ltoreq.y.ltoreq.0.5) oxide superconductor is used in a tunnel junction having a tunneling barrier region with weak superconductivity.
    Type: Grant
    Filed: May 17, 1996
    Date of Patent: March 2, 1999
    Assignees: Fujitsu Ltd., Sharp Kabushiki Kaisha, NEC Corp., International Superconductivity Technology Center
    Inventors: Yoshihiro Ishimaru, Yuuji Mizuno, Katsumi Suzuki, Youichi Enomoto, Shoji Tanaka
  • Patent number: 5873985
    Abstract: An oxide film having a desired pattern is first formed on a magnesia substrate. A superconducting oxide film is then formed on the exposed portion of the magnesia substrate and also on the oxide film. Thus, a tilt-boundary junction is formed in the boundary between the superconducting oxide film portion on the magnesia substrate and the superconducting oxide film portion on the oxide film. The tilt-boundary junction functions as a Josephson junction. By utilizing the Josephson junction in the tilt-boundary junction, a SQUID pattern can be formed on the magnesia substrate to provide a SQUID device.
    Type: Grant
    Filed: March 24, 1993
    Date of Patent: February 23, 1999
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Seiichi Tokunaga, Ryokan Yuasa, Shuji Fujiwara, Masao Nakao, Hiroaki Furukawa
  • Patent number: 5866252
    Abstract: This invention permits superconducting ceramics, as well as other ceramic materials, to be spray deposited onto indefinitely large sheets of metallic substrate from a carboxylic acid salt solution. Elemental metal precursors of the superconductor are introduced into the solution as carboxylic acid salts. The deposit formed on the malleable metallic substrate is then thermomechanically calcined to form c-axis textured metal-superconductor composite sheet structures. These composite sheet structures can be formed by pressing together two ceramic-substrate structures, ceramic face-to-face, to form a metal-ceramic-metal sheet structure, or by overlaying a metal sheet over the deposited structure. Once the structure has been thermomechanically calcined, the c-axis of the superconductor is oriented parallel to the vector defining the plane of the metal sheet, i.e., perpendicular to the surface of the plane.
    Type: Grant
    Filed: October 18, 1996
    Date of Patent: February 2, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: L. Pierre de Rochemont, Michael J. Suscavage, Daniel F. Ryder, Jr., Mikhail Klugerman
  • Patent number: 5861361
    Abstract: A FET type superconducting device comprises a thin superconducting channel, a superconducting source region and a superconducting drain region formed of an oxide superconductor over a principal surface of the substrate, and a gate electrode on a gate insulator disposed on the superconducting channel for controlling the superconducting current flowing through the superconducting channel by a signal voltage applied to the gate electrode. The superconducting channel is formed of(Pr.sub.w Y.sub.1-w)Ba.sub.2 Cu.sub.3 O.sub.7-z (0<w<1, 0<z<1) oxide superconductororY.sub.1 Ba.sub.2 Cu.sub.3-v CO.sub.V O.sub.7-u (0<v<3, 0<u<1) oxide superconductor.These oxide superconductors have smaller carrier densities than the conventional oxide superconductor so that the superconducting channel has a larger thickness than the one funned of the conventional oxide superconductor.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: January 19, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Michitomo Iiyama
  • Patent number: 5849669
    Abstract: A high critical temperature superconducting Josephson device includes a bicrystal substrate formed of a first single crystal substrate and a second single crystal substrate, with end faces of the first and second single crystal substrates having different crystal orientations and being joined to each other. A first superconducting electrode formed of a first film of a high critical temperature superconductor material is located on the first single crystal substrate, whereas a second superconducting electrode formed of a second film of a high critical temperature superconductor material is located on the second single crystal substrate. A bridge is formed of a third film of a high critical temperature superconductor material and located on the bicrystal substrate across a joint between said first and said second single crystal substrates.
    Type: Grant
    Filed: May 30, 1996
    Date of Patent: December 15, 1998
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Zhongmin Wen
  • Patent number: 5821200
    Abstract: A lattice matching device includes a substrate having thereon monocrystal regions having different lattice mismatches with respect to a LnBa.sub.2 Cu.sub.3 O.sub.x superconductor. A superconducting thin film is formed on the substrate, which film consists essentially of a superconductor of LnBa.sub.2 Cu.sub.3 O.sub.x wherein Ln represents yttrium or a lanthanide, and 6<x<7. The first and second superconducting thin film portions have different axes of orientation perpendicular to a main surface of the substrate, and arranged in contact with each other or at a distance which allows transmission of electron pairs from one to another.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 13, 1998
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masashi Mukaida, Shintaro Miyazawa, Junya Kobayashi
  • Patent number: 5789346
    Abstract: Method for manufacturing a superconducting device including forming on a surface of a substrate a non-superconducting oxide layer, a first oxide superconductor thin film, etching the first oxide superconductor thin film so as to form a concave portion, implanting ions to the first oxide superconductor thin film at the bottom of the concave portion so as to form an insulating region such that the first oxide superconductor thin film is divided into two superconducting regions by the insulating region, and forming a second oxide superconductor thin film on the insulating region and the two superconducting regions, which is continuous to the two superconducting regions.
    Type: Grant
    Filed: May 20, 1996
    Date of Patent: August 4, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5776863
    Abstract: A method of in-situ fabrication of a Josephson junction having a laminar structure, the method comprising the steps of: (1) etching a planar substrate to yield a first planar segment, a second planar segment and a ramp segment, the ramp segment connecting the two planar segments at an angle thereto and the substrate having a constantly-decreasing thickness in the ramp segment; (2) depositing a first superconductive layer on the substrate; (3) depositing a non-superconductive layer on the first superconductive layer; and (4) depositing a second superconductive layer on the non-superconductive layer, wherein both the first and second superconductive layers, and the non-superconductive layer are epitaxial with a c-axis in a direction substantially normal to the plane of the first and second planar segments, and the layers are of substantially uniform thickness in the three segments.
    Type: Grant
    Filed: July 8, 1996
    Date of Patent: July 7, 1998
    Assignee: TRW Inc.
    Inventor: Arnold H. Silver
  • Patent number: 5750474
    Abstract: A superconductor-insulator-superconductor Josephson tunnel junction, comprising: a single crystalline substrate having a perovskite crystal structure; a template layer formed of a b-axis oriented PBCO thin film on the substrate; and a trilayer structure consisting of a lower electrode, a barrier layer and an upper electrode, which serve as a superconductor, an insulator and a superconductor, respectively, the lower electrode and the upper electrode each being formed of an a-axis oriented YBCO superconducting thin film and having an oblique junction edge at an angle of 30.degree. to 70.degree., the barrier layer being formed of an insulating thin film between the two superconducting electrodes, can be operated at a low power with an exceptional speed in calculation and data processing.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: May 12, 1998
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Gun-Yong Sung, Jeong-Dae Suh
  • Patent number: 5739084
    Abstract: A method for fabricating a superconducting device with a substrate, a first oxide superconductor thin film, a barrier layer, a diffusion layer, and a second oxide superconductor thin film. The first oxide superconductor thin film with a very thin thickness is formed on the principal surface of the substrate. The barrier layer and the diffusion source layer are formed on a portion of the first oxide superconductor thin film. The second oxide superconductor thin film is grown on an exposed surface of the first oxide superconductor thin film until the barrier and diffusion source layers are embedded in the second oxide superconductor thin film, so that a material of the diffusion source layer is diffused into the second oxide superconductor thin film.
    Type: Grant
    Filed: January 2, 1997
    Date of Patent: April 14, 1998
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5736488
    Abstract: This invention relates to multilayered superconductive composites, particularly to composites based on thallium-containing superconducting oxides, and their process of manufacture.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: April 7, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Dean Willett Face, Kirsten Elizabeth Myers
  • Patent number: 5721196
    Abstract: A Josephson junction device comprises a single crystalline substrate including a principal surface, an oxide layer formed on the principal surface of the substrate having a step on its surface and an oxide superconductor thin film formed on the surface of the oxide layer. The oxide superconductor thin film includes a first and a second portions respectively positioned above and below the step of the oxide layer, which are constituted of single crystals of the oxide superconductor, and a step-edge junction made up of a grain boundary on the step of the oxide layer, which constitutes a weak link of the Josephson junction.
    Type: Grant
    Filed: August 16, 1996
    Date of Patent: February 24, 1998
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Michitomo Iiyama
  • Patent number: 5721195
    Abstract: The planar superconducting resonator includes a substrate (1), a symmetrically shaped stripline (2) applied to the substrate (1) in which two orthogonal electromagnetic modes are excitable and including a symmetry perturbation for coupling the two orthogonal electromagnetic modes, an additional stripline (5) arranged on the substrate in the vicinity of the symmetry perturbation, a Josephson junction (3) arranged between the symmetry perturbation and the additional stripline (5) and a device for generating and controlling a magnetic field at the Josephson junction (3) so that the degree of coupling between the two orthogonal electromagnetic modes is varied. The Josephson junction (3) is formed by a non-superconducting layer (4) arranged between the symmetry perturbation and the additional stripline (5).
    Type: Grant
    Filed: November 1, 1995
    Date of Patent: February 24, 1998
    Assignee: Robert Bosch GmbH
    Inventors: Wolfgang Grothe, Klaus Voigtlaender, Matthias Klauda, Claus Schmidt
  • Patent number: 5719105
    Abstract: A superconducting element is disclosed which includes a substrate and a superconducting layer provided on the substrate and formed of an oxide having the following chemical formula:RBa.sub.2 (Cu.sub.1-x M.sub.x).sub.3 O.sub.7wherein R represents at least one element selected from the group consisting of Y, La, Nd, Pm, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu, M represents at least one element selected from the group consisting of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn and Ga, and x represents a number of less than 1 but greater than 0.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: February 17, 1998
    Assignees: International Superconductivity Technology Center, Matsushita Electric Industrial Co., Ltd., Sanyo Electric Co., Ltd.
    Inventors: Akihiro Odagawa, Youichi Enomoto, Shuuichi Yoshikawa
  • Patent number: 5696392
    Abstract: A conductor suitable for use in oxide-based electronic devices and circuits is disclosed. Metallic oxides having the general composition AMO.sub.3, where A is a rare or alkaline earth or an alloy of rare or alkaline earth elements, and M is a transition metal, exhibit metallic behavior and are compatible with high temperature ceramic processing. Other useful metallic oxides have compositions (A.sub.1-x A'.sub.x)A".sub.2 (M.sub.1-y M'.sub.y).sub.3 O.sub.7-.delta. or (A.sub.1-x A'.sub.x).sub.m (M.sub.1-y M'.sub.y).sub.n O.sub.2m+n, where 0.ltoreq.x, y.ltoreq.1 and 0.5.ltoreq.m, n.ltoreq.3, A and A' are rare or alkaline earths, or alloys of rare or alkaline earths, A' and A" are alkaline earth elements, alloys of alkaline earth elements, rare earth elements, alloys of rare earth elements, or alloys of alkaline earth and rare earth elements, and M and M' are transition metal elements or alloys of transition metal elements.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: December 9, 1997
    Assignee: Conductus, Inc.
    Inventors: Kookrin Char, Theodore H. Geballe, Brian H. Moeckly
  • Patent number: 5691280
    Abstract: A thin film which is substantially free of measurable surface defects due to second-phase inclusions is disclosed. The film is composed of multilayered strata of a first metal oxide interspersed with single molecular layers of a second metal oxide, where the second metal oxide is effective to absorb second-phase defects which form in the first oxide layers.
    Type: Grant
    Filed: May 14, 1996
    Date of Patent: November 25, 1997
    Assignee: Varian Associates, Inc.
    Inventors: James N. Eckstein, Ivan Bozovic
  • Patent number: 5683968
    Abstract: A superconducting device or a super-FET has a pair of superconducting electrode regions (20b, 20c) consisting of a thin film (20) oxide superconductor being deposited on a substrate (5) and a weak/ink region (20a), the superconducting electrode regions (20b, 20c) being positioned at opposite sides of the weak link region (20a), these superconducting electrode regions (20b, 20c) and the weak link region (20a) being formed on a common plane surface of the substrate (5). The weak link region (20a) is produced by local diffusion of constituent element(s) of the substrate (5) and/or a gate electrode insulating layer (16) into the thin film (20) of the oxide superconductor in such a manner that a substantial wall thickness of the thin film (20) of the oxide superconductor is reduced at the weak link region (20a) so as to leave a weak link or superconducting channel (10) in the thin film (20) of oxide superconductor over a non-superconducting region (50) which is produced by the diffusion.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: November 4, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Takao Nakamura, Hiroshi Inada, Michitomo Iiyama
  • Patent number: 5677264
    Abstract: The present invention discloses a process for forming an a-axis superconducting junction by adjusting the deposition temperature of an oxide normal conductor layer/and oxide superconductor layer/an oxide insulating layer/an oxide normal conductor layer/and an oxide superconductor layer, which are sequentially multilayered on an oxide single crystalline substrate. According to the present invention, the oxide superconductor layer and the oxide insulating layer have an a-axis oriented perpendicularly, and the oxide normal conductor layer have a b-axis oriented perpendicularly, so that a superconductor Josephson junction may be obtained.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: October 14, 1997
    Assignee: Electronics & Telecommunications Research Institute
    Inventors: Jeong-Dae Suh, Gun-Yong Sung
  • Patent number: 5661112
    Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.
    Type: Grant
    Filed: July 22, 1988
    Date of Patent: August 26, 1997
    Inventors: Shinichiro Hatta, Hidetaka Higashino, Kumiko Hirochi, Hideaki Adachi
  • Patent number: 5656575
    Abstract: The present invention provides a superconducting device having a weak link junction with an angle at the grain boundary between the two superconductor crystals being variable. The angle at the junction is substantially equivalent to a vicinal angle for the substrate. Accordingly, the magnitude of the angle at the junction can be varied by varying the vicinal angle of the substrate. This result can be realized by using buffer layers of different compositions underlying the superconducting materials on either side of the weak link junction. Weak link junctions and reproducible properties are essential for a variety of electronic and magnetic sensing devices.
    Type: Grant
    Filed: February 13, 1995
    Date of Patent: August 12, 1997
    Assignee: Superconducting Core Technologies, Inc.
    Inventor: Carl H. Mueller
  • Patent number: 5629267
    Abstract: A superconducting element is disclosed which comprises a lower superconducting layer, an upper superconducting layer, and an intermediate layer interposed between the lower and upper superconducting layers. The lower and upper superconducting layers are both form of a superconducting cuprate. The intermediate layer is formed of a layered cuprate containing in the crystal structure thereof multiple fluorite blocks represented by the formula:[B]AE.sub.2 (RE1.sub.1-y RE2.sub.y).sub.m+1 Cu.sub.2 O.sub.z(wherein [B] stands for a block layer, AE for an alkaline earth element, RE1 for at least one element selected from the group consisting of lanthanide elements and actinoid elements which form ions of valency of larger than 3, RE2 for at least one element selected from the group consisting of lanthanide elements which form ions of valency of 3 and yttrium, m for a number satisfying the expression m.gtoreq.2, y for a number satisfying the expression 0.ltoreq.y<1, and z for the oxygen content).
    Type: Grant
    Filed: March 24, 1995
    Date of Patent: May 13, 1997
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Sumio Ikegawa, Tadao Miura
  • Patent number: 5629268
    Abstract: A process for depositing successively a plurality of thin films on a bottom superconductor layer made of oxide superconductor deposited on a substrate in a single chamber under a condition, the bottom superconductor layer is heated in ultra-high vacuum at a temperature which is lower than the oxygen-trap temperature (T.sub.trap) at which oxygen enter into the oxide superconductor but higher than a temperature which is lower by 100.degree. C. than the oxygen-trap temperature (T.sub.trap -100.degree. C.) and then the first thin film is deposited thereon.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: May 13, 1997
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: So Tanaka, Takao Nakamura, Michitomo Iiyama
  • Patent number: 5627139
    Abstract: A HTSC Josephson device wherein the barrier layer is a cubic, conductive material.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: May 6, 1997
    Assignee: The Regents of the University of California
    Inventors: David K. Chin, Theodore Van Duzer
  • Patent number: RE37587
    Abstract: A SQUID includes a substrate and a superconducting current path of a patterned oxide superconductor material thin film formed on a surface of the substrate. A c-axis of an oxide crystal of the oxide superconductor material thin film is oriented in parallel to the surface of the substrate.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: March 19, 2002
    Assignee: Sumitomo Electric Industries Ltd.
    Inventors: Takashi Matsuura, Saburo Tanaka, Hideo Itozaki
  • Patent number: RE36814
    Abstract: Excellent films of a high Tc superconductor are easily produced on metal coated substrates at a temperature below 700.degree. C. These metal buffer films are made of Pt, Au, Ag, Pd, Ni or Ti. The film superconductivity is significantly improved by the metal buffer layer. Since it is easy to form this metal coating on a substrate, the invention can increase the potential number of usable substrates such as fibers, amorphous solids or semiconductors.
    Type: Grant
    Filed: March 6, 1998
    Date of Patent: August 8, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shinichiro Hatta, Hidetaka Higashino, Kumiko Hirochi, Hideaki Adachi