A device includes: a first chip including a qubit; and a second chip bonded to the first chip, the second chip including a substrate including first and second opposing surfaces, the first surface facing the first chip, wherein the second chip includes a single layer of superconductor material on the first surface of the substrate, the single layer of superconductor material including a first circuit element. The second chip further includes a second layer on the second surface of the substrate, the second layer including a second circuit element. The second chip further includes a through connector that extends from the first surface of the substrate to the second surface of the substrate and electrically connects a portion of the single layer of superconducting material to the second circuit element.

Electrical, mechanical, computing, and/or other devices that include components formed of extremely low resistance (ELR) materials, including, but not limited to, modified ELR materials, layered ELR materials, and new ELR materials, are described.

High temperature superconductor (HTS)-based interconnect systems comprising a cable including HTS-based interconnects are described. Each of the HTS-based interconnects includes a first portion extending from a first end towards an intermediate portion and a second portion extending from the intermediate portion to a second end. Each of the HTS-based interconnects includes a substrate layer formed in the first portion, in the intermediate portion, and in the second portion, a high temperature superconductor layer formed in at least a sub-portion of the first portion, in the intermediate portion, and in the second portion, and a metallic layer formed in the first portion and in at least a sub-portion of the intermediate portion. The HTS-based interconnect system includes a thermal load management system configured to maintain the intermediate portion of each of the HTS-based interconnects at a predetermined temperature in a range between a temperature of 60 kelvin and 92 kelvin.

Superconducting through substrate vias (STSVs) are disclosed. The STSVs provide superconducting interconnections between opposite faces of a substrate. In an example, a method of forming STSVs includes etching openings that extend from a first side of a substrate partially through the substrate towards a second side of the substrate. The method also includes depositing a seed layer over the first side of the substrate and interior surfaces of the openings in the substrate. The method further includes forming a resist or hardmask on the first side of the substrate above the seed layer, such that the resist or hardmask comprises openings aligned with the etched openings in the substrate. The etched openings in the substrate are filled with a superconducting filler material. The substrate is thinned by removing material from the second side of the substrate until the deposited seed layer is exposed on the second side of the substrate.

An integrated circuit comprises a first circuit element operably connected to a second circuit element by a nanowire interconnect; wherein the nanowire interconnect comprises molybdenum phosphide (MoP), tungsten phosphide (WP.sub.2), or niobium phosphide (NbP). A nanowire interconnect can be made by providing a template nanowire; providing a phosphine source; producing phosphine from the phosphine source; and contacting the template nanowire with the phosphine. The nanowire interconnect demonstrates low resistance.

An airbridge implements connections on a superconducting chip. It comprises a strip of superconductive material between a first superconductive area and a second superconductive area. A first end of said strip comprises a first planar end portion attached to and parallel with said first superconductive area, and a second end of said strip comprises a respective second planar end portion. A middle portion is located between said first and second planar end portions, forming a bend away from a plane defined by the surfaces of the first and second superconductive areas. First and second separation lines separate the end portions from the middle portion. At least one of said first and second separation lines is directed otherwise than transversally across said strip.

To provide a superconducting device capable of more accurately arranging a non-contact coupling circuit of a superconducting integrated circuit chip and a non-contact coupling circuit of a circuit board. The chip has a first electrode made of a first superconducting material and a first non-contact coupling circuit on a surface thereof. The board has a second electrode made of a second superconducting material and a second non-contact coupling circuit on a surface thereof, and is arranged to face the chip. The second electrode has a protrusion protruding toward the chip. The protrusion includes a flat upper surface. The first electrode has a flat surface and a first recess. The first recess is arranged to face the upper surface to be located inside the upper surface of the protrusion. A third superconducting material connecting the upper surface and the first recess.

A cryogenic electronic package includes at least two superconducting and/or conventional metal semiconductor structures. Each of the semiconductor structures includes a substrate and a superconducting trace. Additionally, each of the semiconductor structures includes a passivation layer and one or more under bump metal (UBM) structures. The cryogenic electronic package also includes one or more superconducting and/or conventional metal interconnect structures disposed between selected ones of the at least two superconducting semiconductor structures. The interconnect structures are electrically coupled to respective ones of the UBM structures of the semiconductor structures to form one or more electrical connections between the semiconductor structures. A method of fabricating a cryogenic electronic package is also provided.

A method of forming a composite crystalline nitride structure is provided. The method includes depositing a first crystalline nitride layer on a substrate, patterning the first crystalline nitride layer to form a patterned crystalline nitride layer having a top surface and that includes undulations, annealing the patterned crystalline nitride layer at a temperature between 300° C. to 850° C. to form an annealed patterned crystalline nitride layer, and depositing a second crystalline nitride layer on the annealed patterned crystalline nitride layer. The second crystalline nitride layer is lattice-matched to the underlying annealed patterned crystalline nitride layer to within 2%, thereby forming the composite crystalline nitride structure.

A method comprising forming a trench in a substrate and forming a first Ti layer on the top surface of the substrate, such that, the first Ti layer is formed on the exposed surface of the trench. Forming a Nb layer on an exposed top surface of first Ti layer and forming a second Ti layer on the exposed top surface of the Nb layer. Planarizing the second Ti layer, the Nb layer, and the first Ti layer to the top surface of the substrate, wherein the second Ti layer, the Nb layer, and the first Ti layer remain within the trench, wherein the Nb layer has at least two surfaces exposed during the planarizing process.