The present invention relates to a phononic-isolated Kinetic Inductance Detector (KID) and a method of fabrication thereof. The KID is a highly sensitive superconducting cryogenic detector which can be scaled to very large format arrays. The fabrication process of the KID of the present invention integrates a phononic crystal into a KID architecture. The phononic structures are designed to reduce the loss of recombination and athermal phonons, resulting in lower noise and higher sensitivity detectors.

The invention relates to a (RE,Y)-123 superconducting film containing mixed artificial pinning centers and a preparation method thereof, wherein a stoichiometric ratio of Cu in a parent phase of the (RE,Y)-123 superconducting film is 3.05-5; the mixed artificial pinning centers include a perovskite structure BaMO3 and a double-perovskite structure oxide Ba2(RE,Y)NO6; and a total mole percentage of Ba2(RE,Y)NO6 in the superconducting film is not less than 2.5%. The mixed artificial pinning centers form well-aligned column structures along the thickness direction in the superconducting film. The invention is intended not only to solve the problem that a single secondary phase cannot be well aligned along the thickness direction of (RE,Y)-123 when using the high-speed pulsed laser deposition technique, but also to effectively overcome the film thickness effect of the (RE,Y)-123 superconducting film containing mixed artificial pinning centers, hence the in-field current carrying capacity of the superconducting film is significantly improved in industrialized high-speed production.

A superconducting structure is presented. In some embodiments, the superconducting structure includes a first plane of material; a second plane of material; and a separating medium positioned between the first plane and the second plane, wherein a superconducting critical temperature of the superconducting structure is adjusted by control of one or more parameters.

An ultra-thin film superconducting tape and method for fabricating same is disclosed. Embodiments are directed to a superconducting tape being fabricated by processes which include removing a portion of the superconducting tape's substrate subsequent the substrate's initial formation, whereby a thickness of the superconducting tape is reduced to 15-80 μm.

A superconducting coil according to an embodiment includes: a winding frame; a superconducting wire wound around the winding frame and having a first region and a second region facing the first region in a coil radial direction; and a resin layer located between the first region and the second region and including particles, an epoxy resin surrounding the particles, and a region existing between the particle and the epoxy resin, the region including silane containing a phenylamino group. The average particle diameter of the particles is equal to or more than 1 μm and equal to or less than 5 μm, and the volume ratio of the particles in the resin layer is equal to or more than 50% and equal to or less than 66%.

Certain embodiments involve processes or systems for creating various high-temperature superconductive structures or materials. For example, a method can involve depositing a first layer of boron and a second layer of un-doped amorphous carbon on a substrate. The un-doped amorphous carbon is ferromagnetic. The first layer of boron and the second layer of un-doped amorphous carbon are melted by a laser pulse to form a melted boron-doped amorphous carbon. The melted boron-doped amorphous carbon is quenched to create a quenched boron-doped amorphous carbon that is diamagnetic and superconducting. The quenched melted boron-doped amorphous carbon includes a mixture of sp3 bonded carbon atoms and sp2 bonded carbon atoms and a superconducting transition temperature of the quenched boron-doped amorphous carbon is much higher than diamond and increases based on a boron concentration. Undoped Q-carbon is ferromagnetic with Curie temperature above 500K.

A method of fabricating a superconductor device includes providing a first metal layer on top of the substrate. An oxidation of a top surface of the first metal layer is rejected. A second metal layer is deposited on top of the second metal layer. A superconducting alloy of the first metal layer and the second metal layer is created between the first metal layer and the second metal layer. There is no oxide layer between the superconducting alloy and the first metal layer.

A superconductor thermal filter is disclosed that includes a normal metal layer having a first side, an insulating layer overlying the first side of the normal metal layer, and a multilayer superconductor structure having a first side overlying a side of the insulating layer opposite the side that overlies the normal metal layer. The multilayer superconductor structure is comprised of a plurality of superconductor layers with each superconductor layer having a smaller superconducting energy band gap than the preceding superconductor as the superconductor layers extend away from the normal metal layer. The thermal filter further includes a normal metal layer quasiparticle trap having a first side and a second side with the first side being disposed on a second side of the multilayer superconductor. A bias voltage is applied between the normal metal layer and the normal metal layer quasiparticle trap to remove hot electrons from the normal metal layer.

A method and a device for preparing an inductance element, an inductance element, and a superconducting circuit are provided. The method includes acquiring a compound for preparing an inductance element, a superconducting coherence length and a magnetic field penetration depth of the compound meeting a preset condition; and annealing the compound to cause decomposition between a non-superconductor phase and a superconductor phase in the compound to generate the inductance element, the kinetic inductance of the inductance element being greater than the geometric inductance of the inductance element.

According to an embodiment of the present invention, a method for fabricating a Majorana fermion structure includes providing a substrate, and depositing a superconducting material on the substrate. The method includes depositing a magnetic material on the superconducting material using angled deposition through a mask. The method includes annealing the magnetic material and the superconducting material to form a magnetic nanowire partially embedded in the superconducting material such that the magnetic nanowire and the superconducting material form a Majorana fermion structure.