A method for manufacturing a superconductor is described. A metal assembly precursor can be formed within a hollow copper support element. Forming the metal assembly precursor within a hollow copper support element by positioning a plurality of conductor elements about a core including Sn to provide a first plurality of inner interstitial spaces between the plurality of conductor elements between the core and conductor elements and a second plurality of outer interstitial spaces between the hollow copper support element and the core, the plurality of conductor elements including unreacted Nb. The metal assembly precursor can be reduced via cold drawing to produce a reduced metal assembly. The reduced metal assembly can be reaction heat treated so that the unreacted Nb undergoes a phase transformation to a reacted superconductor.

A device, system and method for measuring the temperature at the center of a normal hotspot and the heat escape time in superconducting filament or nanowire toward the substrate. The device includes structured layers; a superconducting filament is implemented as an active layer where an electrical current pulse or single photon radiation generates a hot spot; a sensitive semiconductor layer of germanium serves as a temperature sensor (thermometer); and a thin layer of insulating silicon oxide is intercalated between the superconducting layer and the germanium having a thickness in the range of 2-10 nm and width 5-100 m. This device provides a direct measurement of the temperature at the center of a hot spot and determination of the heat escape time toward a substrate; and can be used to determine the sensitivity of a superconducting single photon detector device to a next upcoming photon.

A method of fabricating a device, wherein the device comprises a plurality of lengths of material and at least one junction joining two or more of the lengths of material. In a masking phase, a mask is formed on an underlying layer of the device. The mask comprises a plurality of trenches exposing the underlying layer, each trench corresponding to one of the lengths of material. A respective section of two or more of the trenches either (a) narrow down, or (b) are separated by a discontinuity, at a position corresponding to the at least one junction. In a selective area growth phase, material is grown in the set of trenches to form the lengths of material on the underlying layer. The two or more lengths of material are joined at the at least one junction.

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

Methods for electrodeposition using aqueous electrolytes where water molecules are depleted are described herein. Methods of electrodepositing superconducting thin films from aqueous electrolytes where water molecules are depleted are also described herein.

A multi-filament high temperature superconducting cable having improved AC current carrying capacity, quench resistance and flexibility. The multi-filament cable is formed from a plurality of stacked exfoliated filaments which provide current sharing between adjacent superconducting layers.

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.

A multi-filament high temperature superconducting cable having improved AC current carrying capacity, quench resistance and flexibility. The multi-filament cable is formed from a plurality of stacked exfoliated filaments which provide current sharing between adjacent superconducting layers.

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 monofilament (100) for producing an Nb.sub.3Sn-containing superconductor wire (33) includes a powder core (1) with an Sn-containing powder, a reaction tube (3) composed of an Nb alloy that includes Nb and at least one further alloy component X. The powder core is disposed within the reaction tube. The monofilament also includes at least one source (4) for at least one partner component Pk. A respective source includes one or more source structures at a unitary radial position in the monofilament. The alloy component X and the partner component Pk form precipitates XPk on reaction annealing of the monofilament in which Sn from the powder core and Nb from the reaction tube react to produce Nb.sub.3Sn. The powder core is disposed in a moderation tube, which in turn is disposed within the reaction tube. This provides a monofilament for a powder-in-tube based Nb.sub.3Sn-containing superconductor wire with improved current carrying capacity.