Provided are a Sn—Ti alloy powder for a superconducting wire, the Sn—Ti alloy powder making it possible to improve superconducting characteristics by minimizing the size of Sn—Ti particles dispersed in a Sn-based alloy, a method for preparing the same, and a method for manufacturing a superconducting wire using the same, wherein a Sn—Ti alloy is melted to produce a Sn—Ti intermetallic compound having an average particle size of 3 μm or less, and a content of Ti in the entire alloy is 0.5 wt % to 3 wt %, and the method of preparing the Sn—Ti alloy powder for a superconducting wire includes: a Sn—Ti alloy melting step of melting a Sn—Ti alloy or a Sn—Ti alloy processed material; and a Sn—Ti alloy powder formation step of spraying and solidifying a molten Sn—Ti alloy through a nozzle in an inert gas atmosphere.

A superconducting device is described wherein the device comprises a substrate; a capacitor structure (604) and a superconducting inductor structure (602) disposed on the substrate, the capacitor structure an the superconducting inductor structure forming a superconducting microwave filter structure, in particular a low-pass filter, the superconducting inductor structure including a plurality of nanowires of a superconducting material, each of the plurality of nanowires being galvanically connected to one of a plurality of capacitor electrodes (608) forming the capacitor structure, wherein the cross-sectional dimensions of the plurality of nanowires are selected such that the kinetic inductance of each of the one or more nanowires is larger, preferably substantially larger, than the geometrical inductance of the nanowire.

The invention concerns an inteconnect device for interconnection between lines of superconducting material at least one via in contact with those lines, comprising:

a) a first substrate, which carries at least one first line of a first superconducting material;
b) at least one first via of a second superconducting material, different from the first superconducting material, said at least one first line being disposed between said first substrate and said first via;
c) at least one second line above said first via and in contact with the latter.

A vertical Josephson Junction (JJ) qubit device that is fabricated from crystalline silicon material is provided. The JJ device has a substrate of epitaxial silicon, a lower superconducting electrode that is a superconducting region of the epitaxial silicon and an upper superconducting electrode of a metallic superconductor. The JJ device also has a junction layer. A section of the junction layer between the lower and upper superconducting electrodes forms a junction of the JJ device. Resonator and/or capacitor wiring of the JJ device is also fabricated using the metallic superconductor. The superconducting region is epitaxial silicon that is doped or implanted with boron or gallium. The substrate, the junction layer, and the implanted epitaxial silicon share a contiguous crystalline structure.

A qubit coupling device includes: a dielectric substrate including a trench; a first superconductor layer on a surface of the dielectric substrate where an edge of the first superconductor layer extends along a first direction and at least a portion of the superconductor layer is in contact with the surface of the dielectric substrate, and where the superconductor layer is formed from a superconductor material exhibiting superconductor properties at or below a corresponding critical temperature; a length of the trench within the dielectric substrate is adjacent to and extends along an edge of the first superconductor layer in the first direction, and where the electric permittivity of the trench is less than the electric permittivity of the dielectric substrate.

In various embodiments, superconducting wires incorporate diffusion barriers composed of Ta alloys that resist internal diffusion and provide superior mechanical strength to the wires.

A method of fabricating a device including a superconductive layer includes depositing a seed layer on a substrate, exposing the seed layer to an oxygen-containing gas or plasma to form a modified seed layer, and after exposing the seed layer to the oxygen-containing gas or plasma depositing a metal nitride superconductive layer directly on the modified seed layer. The seed layer is a nitride of a first metal, and the superconductive layer is a nitride of a different second metal.

A method for producing an at least two-part structure, such as a semifinished product for a superconducting wire is provided. A first structure and a second structure are separately produced, and the first structure and the second structure are then inserted one into the other. The first structure and the second structure are respectively produced in layers by selective laser melting or selective electron beam melting of a powder. The method produces two-part structures for semifinished products of superconducting wires.

A system and method for treating a cavity comprises arranging a niobium structure in a coating chamber, the coating chamber being arranged inside a furnace, coating the niobium structure with tin thereby forming an Nb.sub.3Sn layer on the niobium structure, and doping the Nb.sub.3Sn layer with nitrogen, thereby forming a nitrogen doped Nb.sub.3Sn layer on the niobium structure.

In various embodiments, superconducting wires feature assemblies of clad composite filaments and/or stabilized composite filaments embedded within a wire matrix. The wires may include one or more stabilizing elements for improved mechanical properties.