A method for etching a surface including obtaining a structure comprising a plurality of nanowires on or above a substrate and a dielectric layer on or above the nanowires, wherein the dielectric layer comprises protrusions formed by the underlying nanowires; reacting a surface of the dielectric layer with a reactant, comprising a gas or a plasma, to form a reactive layer on the dielectric layer, wherein the reactive layer comprises a chemical compound including the reactant and elements of the dielectric layer and the reactive layer comprises sidewalls defined by the protrusions; and selectively etching the reactive layer, wherein the etching etches the protrusions laterally through the sidewalls so as to planarize the surface and remove or shrink the protrusions.

The present invention addresses a problem of providing an MgB2 wire material having a small reversible bending radius, a superconducting coil using the same, and an MRI without lowering a critical current value and a critical current density of the MgB2 wire material to an extreme. To solve the problem, provided are a superconducting wire having a plurality of MgB2 strands and a first base metal, a superconducting coil using the same, and an MRI, the superconducting wire being characterized in that in a cross section orthogonal to a wire longitudinal direction, a center point of an area surrounded by the plurality of MgB2 strands and a center axis of a cross section of the superconducting wire are disposed in separated positions.

A magnesiumdiboride (MgB.sub.2) powder-in-tube (PIT) wire has a cross-section showing —voids, —magnesiumdiboride, and —oxides, as measured by energy-dispersive X-ray spectroscopy. Oxides are located at the borders between the voids and the magnesiumdiboride. The MgB.sub.2 PIT wire has a higher degree of superconductivity.

Techniques regarding qubit devices comprising silicon-based Josephson junctions and/or the manufacturing of qubit devices comprising silicon-based Josephson junctions are provided. For example, one or more embodiments described herein can comprise an apparatus that can include a Josephson junction comprising a tunnel barrier positioned between two vertically stacked superconducting silicon electrodes.

Methods and structures corresponding to superconducting apparatus including superconducting layers and traces are provided. A method for forming a superconducting apparatus includes forming a first dielectric layer on a substrate by depositing a first dielectric material on the substrate and curing the first dielectric material at a first temperature. The method further includes forming a first superconducting layer comprising a first set of patterned superconducting traces on the first dielectric layer. The method further includes forming a second dielectric layer on the first superconducting layer by depositing a second dielectric material on the first superconducting layer and curing the second dielectric material at a second temperature, where the second temperature is lower than the first temperature. The method further includes forming a second superconducting layer comprising a second set of patterned superconducting traces on the second dielectric layer.

A system and method for fabricating accelerator cavities comprises forming at least two half cavities and joining the half cavities with a longitudinal seal. The half cavities can comprise at least one of aluminum, copper, tin, and copper alloys. The half cavities can be coated with a superconductor or combination of materials configured to form a superconductor coating.

Techniques regarding qubit devices comprising silicon-based Josephson junctions and/or the manufacturing of qubit devices comprising silicon-based Josephson junctions are provided. For example, one or more embodiments described herein can comprise an apparatus that can include a Josephson junction comprising a tunnel barrier positioned between two vertically stacked superconducting silicon electrodes.

Proposed is a novel embedded structure for suppressing a disturbance in the cross sectional shape and a non-uniform deformation of a metal member arising in a precursor when producing an MgB2 multi-core wire material by a surface reduction process. This superconductive multi-core wire material precursor is characterized by having: soft Cu and Fe pure metals disposed in the center; mixed powder elements, each comprising as a sheath material a metal such as Fe or Nb having a barrier effect preventing a reaction between Mg and Cu, the mixed powder elements being disposed in a form that surrounds the periphery of the soft metal serving as the central material; and disposed around these, an outer shell layer produced from a harder metal than the central material and the sheath material.

A superconducting wire connector includes superconducting wires and a sintered body containing MgB.sub.2. The superconducting wires are connected by the sintered body. At least one of the superconducting wires includes a superconducting core having a first outer surface. The sintered body is in contact with the first outer surface. A method of connecting superconducting wires by a sintered body containing MgB.sub.2 includes exposing a superconducting core of at least one of the superconducting wires by removing a portion, positioned in the middle in a longitudinal direction of the at least one of the superconducting wires, of a metal sheath disposed around the superconducting core, disposing the at least one of the superconducting wires through a container, filling the container with a raw material of MgB.sub.2, and forming the sintered body being in contact with an outer surface of the superconducting core by sintering the raw material filled in the container.

According to an exemplary embodiment of the present invention, provided is a method for manufacturing a superconductor including magnesium diboride, the method including: a first mixture preparation step of preparing a first mixture including a boron powder and a liquid chlorinated hydrocarbon compound; a second mixture preparation step of preparing a second mixture including the first mixture and a magnesium powder; a molded body manufacturing step of manufacturing a molded body by pressurizing the second mixture; and a sintering step of sintering the molded body to manufacture a superconductor including magnesium diboride.