Disclosed herein are superconducting wires. The superconducting wires can comprise a metallic matrix and at least one continuous subelement embedded in the matrix. Each subelement can comprise a non-superconducting core, a superconducting layer coaxially disposed around the non-superconducting core, and a barrier layer coaxially disposed around the superconducting layer. The superconducting layer can comprise a plurality of Nb.sub.3Sn grains stabilized by metal oxide particulates disposed therein. The Nb.sub.3Sn grains can have an average grain size of from 5 nm to 90 nm (for example, from 15 nm to 30 nm). The superconducting wire can have a high-field critical current density (J.sub.c) of at least 5,000 A/mm.sup.2 at a temperature of 4.2 K in a magnetic field of 12 T. Also described are superconducting wire precursors that can be heat treated to prepare superconducting wires, as well as methods of making superconducting wires.

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 and system for manufacturing a superconducting material is described. In one embodiment, a layer of refractory cushion is placed over a spool. A first layer of superconducting cable is wound over the first layer of refractory cloth. The superconducting cable is reaction heat-treated on the spool. A first layer of refractory fabric can be placed over the layer of refractory cushion. One or more adjustment mechanisms can be disposed between the first layer of the superconducting cable and the spool.

Disclosed herein are superconducting wires. The superconducting wires can comprise a metallic matrix and at least one continuous subelement embedded in the matrix. Each subelement can comprise a non-superconducting core, a superconducting layer coaxially disposed around the non-superconducting core, and a barrier layer coaxially disposed around the superconducting layer. The superconducting layer can comprise a plurality of Nb.sub.3Sn grains stabilized by metal oxide particulates disposed therein. The Nb.sub.3Sn grains can have an average grain size of from 5 nm to 90 nm (for example, from 15 nm to 30 nm). The superconducting wire can have a high-field critical current density (J.sub.c) of at least 5,000 A/mm.sup.2 at a temperature of 4.2 K in a magnetic field of 12 T. Also described are superconducting wire precursors that can be heat treated to prepare superconducting wires, as well as methods of making superconducting wires.

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

The present invention relates to the use of gallium beam lithography to form superconductive structures. Generally, the method includes exposing a surface to gallium to form an implanted region and then removing material adjacent to and/or below that implanted region. In particular embodiments, the methods herein provide microstructures and nanostructures in any useful substrate, such as those including niobium, tantalum, tungsten, or titanium.

The flexible superconducting micro-coaxial cable is designed for use in quantum computing systems. The micro-coaxial cable includes an inner conductor made of a first superconductive material, surrounded by a dielectric layer. Circumferentially surrounding the dielectric layer is a braided outer conductor, made of a second superconductive material, providing more than 90% coverage. The first and second superconductive materials can be either type-I superconductors, such as Aluminum (Al), Lead (Pb), Titanium (Ti), Indium (In), and Tin (Sn), or type-II superconductors, including magnesium diboride (MgB2), niobium-titanium (NbTi), niobium-tin (Nb3Sn), and niobium-germanium (Nb3Ge).

A compound superconducting wire 10 includes a reinforcement portion 12 and a compound superconductor 11. In the reinforcement portion 12, an assembly of plural reinforcement elements 4 are disposed. The reinforcement elements 4 each include plural reinforcement filaments 1 disposed in a stabilizer 2, and a stabilizing layer 3 at the outer periphery thereof. The reinforcement filaments 1 each mainly contain one or more metals selected from the group consisting of Nb, Ta, V, W, Mo, Fe, and Hf, an alloy consisting of two or more metals selected from the aforementioned group, or an alloy consisting of copper and one or more metals selected from the aforementioned group.

Problem There is proposed an innovative cross-sectional structure, with an idea contrary to the conventional one, utilizing the non-reactivity between Cu and Ta (or between Ag and Nb, Ta) in a high-temperature short-time heat treatment, thus achieving (1) the suppression of the low magnetic-field instability, (2) excellent wire drawability of a precursor wire, and (3) the reduction of the cost required for the incorporation of a stabilizer. Means for Resolution There is proposed a structure having an assembly of a plurality of single wires, wherein the assembly is covered with an outer cover (skin) formed from Nb or Ta, wherein each of the single wires has an Nb/Al composite filament region which is formed from a composite of Nb and Al mixed in an Nb:Al molar ratio of 3:1, and which is covered with a partition formed from Nb or Ta, and further covered with an interfilamentary barrier formed from Cu or Ag disposed around the partition.

A monofilament (1) for the production of a superconducting wire (20) has a powder core (3) that contains at least Sn and Cu, an inner tube (2), made of Nb or an alloy containing Nb, that encloses the powder core (3), and an outer tube (4) in which the inner tube (2) is arranged. The outer side of the inner tube (2) is in contact with the inner side of the outer tube (4) and the outer tube (4) is produced from Nb or from an alloy containing Nb. The outer tube is disposed in a cladding tube. The superconducting current carrying capacity of the superconducting wire is thereby improved.