Superconducting cables employ one or more superconducting tapes wound around a former. A compact superconducting cable is configured using a former having a small diameter, e.g., less than 10 millimeters. A flexible superconducting cable is configured with a former made of a flexible material. Superconducting tape conductors are wound around the former, with the superconducting layer in compression on the inside of the wind turns of the wind, to prevent irreversible damage to the superconductor. A layer of solder is on the superconducting tape(s) or solder sheaths are wound between tape conductors in each layer. The one or more solder layers or sheaths are melted to cause the solder to flow within the structure, to bond some or all of the superconducting tape conductors together and form a mechanically strong cable with an enhanced level of electrical connectivity between tapes in the cable.

A superconductor tape includes a plurality of conductive strips having respective long directions parallel to a long tape direction of the superconductor tape, where each of the plurality of conductive strips separated from one another by a inter-strip region. The superconductor tape further includes a superconductor layer disposed adjacent the plurality of conductive strips, having a length along the long tape direction, where the superconductor layer comprises a plurality of superconductor strips disposed under the respective plurality of conductive strips, and a non-superconductor strip disposed adjacent the inter-strip region.

A transistor includes (i) a first wire including a semiconducting component configured to operate in an on state at temperatures above a semiconducting threshold temperature and (ii) a second wire including a superconducting component configured to operate in a superconducting state while: a temperature of the superconducting component is below a superconducting threshold temperature and a first input current supplied to the superconducting component is below a current threshold. The semiconducting component is located adjacent to the superconducting component. In response to a first input voltage, the semiconducting component is configured to generate an electromagnetic field sufficient to lower the current threshold such that the first input current exceeds the lowered current threshold.

An active cooling structure, comprising a non-superconducting layer, a superconducting layer, and an array of Superconductor-Insulator-Normal Metal (NIS) tunnel junctions. The non-superconducting layer may comprise a plurality of non-superconducting traces. The superconducting layer may comprise a plurality of superconducting traces. The array of Superconductor-Insulator-Normal Metal (NIS) tunnel junctions may be located between the plurality of non-superconducting traces and the plurality of superconducting traces.

Apparatus and methods relating to programmable superconducting cells are described. A programmable superconducting cell can be formed from a superconducting current loop having at least two terminals connected to the loop. The current loop and terminals can be formed from a single layer of superconducting material. The programmable superconducting cell can be incorporated into a crossbar architecture to form a high-speed vector-matrix multiplying processor for deep neural network computations.

A transistor includes (i) a first wire including a semiconducting component configured to operate in an on state at temperatures above a semiconducting threshold temperature and (ii) a second wire including a superconducting component configured to operate in a superconducting state while: a temperature of the superconducting component is below a superconducting threshold temperature and a first input current supplied to the superconducting component is below a current threshold. The semiconducting component is located adjacent to the superconducting component. In response to a first input voltage, the semiconducting component is configured to generate an electromagnetic field sufficient to lower the current threshold such that the first input current exceeds the lowered current threshold.

According to an embodiment, a superconducting wire includes a substrate, an intermediate layer formed on the substrate, a superconducting layer formed on the intermediate layer, and a protective layer formed on the superconducting layer. The superconducting layer has a first portion, a second portion, and a third portion between the first portion and the second portion in the longitudinal direction of the superconducting wire. The protective layer on the third portion is at least partially removed.

A device that is a combination of a superconducting nanowire single-photon detector and a superconducting multi-level memory. These devices can be used to count a number of photons impinging on the device through single-photon to single-flux conversion. Electrical characterization of the device demonstrates single-flux quantum (SFQ) separated states. Optical measurements using attenuated laser pulses with different mean photon number, pulse energies and repetition rates are shown to differentiate single-photon detection from other possible phenomena, such as multiphoton detection and thermal activation. Array devices and methods are also discussed.

A solid state cooler device is disclosed that includes a first superconductor shunt, a first normal metal pad disposed on the first superconductor shunt, and a first insulator layer and a second insulator layer disposed on the normal metal pad and separated from one another by a gap. The solid state cooler device also includes a first superconductor pad disposed on the first insulator layer and a second superconductor pad disposed on the second insulator layer, a first conductive pad coupled to the first superconductor pad, and a second conductive pad coupled to the second superconductor pad. Hot electrons are removed from the first normal metal pad when a bias voltage is applied between the first conductive pad and the second conductive pad, wherein the first superconductor shunt facilitates even current distribution through the device.

A device that is a combination of a superconducting nanowire single-photon detector and a superconducting multi-level memory. These devices can be used to count a number of photons impinging on the device through single-photon to single-flux conversion. Electrical characterization of the device demonstrates single-flux quantum (SFQ) separated states. Optical measurements using attenuated laser pulses with different mean photon number, pulse energies and repetition rates are shown to differentiate single-photon detection from other possible phenomena, such as multiphoton detection and thermal activation. Array devices and methods are also discussed.