The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting switch devices. In one aspect, an electrical circuit includes: (1) a switch device configured to switch between an on state and an off state in response to a first voltage, the switch device comprising: (a) a superconductor layer adapted to transition from a superconducting state to an insulating state in response to a first strain; and (b) a piezoelectric layer positioned adjacent to the superconductor layer, the piezoelectric layer configured to apply the first strain to the superconductor layer in response to the first voltage; (2) a voltage source electrically coupled to the piezoelectric layer of the switch device and configured to supply the first voltage; and (3) an output component coupled to the superconductor layer of the switch device.

The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting switch devices. In one aspect, an electrical circuit includes: (1) a switch device configured to switch between an on state and an off state in response to a first voltage, the switch device comprising: (a) a superconductor layer adapted to transition from a superconducting state to an insulating state in response to a first strain; and (b) a piezoelectric layer positioned adjacent to the superconductor layer, the piezoelectric layer configured to apply the first strain to the superconductor layer in response to the first voltage; (2) a voltage source electrically coupled to the piezoelectric layer of the switch device and configured to supply the first voltage; and (3) an output component coupled to the superconductor layer of the switch device.

An electronic device (e.g., a superconducting memory cell) includes a substrate and a layer of superconducting material disposed over the substrate. The layer of superconducting material is patterned to form a plurality of distinct instances of the layer of superconducting material including: a first wire; and a loop that is (i) distinct and separate from the first wire and (ii) capacitively coupled to the first wire while the loop and the first wire are in a superconducting state. The loop is configured to form a persistent current via the capacitive coupling in response to a write current applied to the first wire while the loop and the first wire are in the superconducting state. The persistent current represents a logic state of the electronic device.

The various implementations described herein include methods, devices, and systems for detecting light. In one aspect, a photodetector device includes: a superconducting wire, and a transistor that includes a semiconducting component and a superconducting component. The superconducting wire is electrically coupled to the superconducting component. The semiconducting component is located adjacent to the superconducting component. The superconducting component is configured to, in response to receiving an input current exceeding a current threshold, transition from a superconducting state to a non-superconducting state and generate heat sufficient to increase a temperature of the semiconducting component from a temperature below a semiconducting threshold temperature to a temperature above the semiconducting threshold temperature.

According to an embodiment, a radiation detector includes a plurality of absorbers, a resistor, and a heat bath member. The absorbers absorb radiation. The resistor undergoes a change in resistance according to a change in temperature of the absorbers. The heat bath member is maintained at a temperature at which resistance of the resistor becomes equal to a specific resistance value, and is positioned to be in thermal contact with the resistor. The absorbers are positioned to be in contact with the resistor, and are arranged at a distance from each other.

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 cascading microwave switch (cascade) includes a set of Josephson devices, each Josephson device in the set having a corresponding operating bandwidth of microwave frequencies, wherein different operating bandwidths have different corresponding center frequencies. A series coupling is formed between first Josephson device from the set and an n.sup.th Josephson device from the set, wherein the series coupling causes the first Josephson device in an open state to reflect back to an input port of the first Josephson device a signal of a first frequency from a frequency multiplexed microwave signal (multiplexed signal) and the n.sup.th Josephson device in the open state to reflect back to an input port of the n.sup.th Josephson device a signal of an n.sup.th frequency from the multiplexed signal.

A photon detector including a graphene-insulating-superconducting junction configured as a temperature sensor. Photons are absorbed by the graphene sheet of the graphene-insulating-superconducting junction, each absorbed photon causing a temporary increase in the temperature of the graphene sheet, and a corresponding change in the differential impedance of the graphene-insulating-superconducting junction. The graphene-insulating-superconducting junction is part of a resonant circuit connected as a shunt load between a radio frequency input transmission line and a radio frequency output transmission line. The transmission S-parameter from input to output is affected by the impedance of the resonant circuit which in turn is affected by the differential impedance of the graphene-insulating-superconducting junction, and therefore by the temperature of the graphene sheet. The absorption of photons is detected by detecting changes in the transmission S-parameter indicating temperature changes caused by the absorption of a photon.

An optical device includes a photonically controlled Josephson Junction and a Faraday rotator cell magnetized by the Josephson Junction.

A multiple arrayed parallel nanowire device includes one or more arrays connected in series, wherein each array includes a plurality of narrow nanowires flanked by one or more wide nanowires, a top electrode, an applied current, a bottom ground electrode, and one or more lateral electrodes where one or more currents or one or more probing voltages can be applied to detect voltage changes in each array. The device detects single and multiple photons without destroying superconductivity in all the nanowires in the array and is thus capable of remaining sensitive to subsequent photon impacts. Moreover, the device can resolve the location of each photon impact.