Abstract: The various embodiments described herein include methods, devices, and systems for operating superconducting circuitry. In one aspect, a programmable circuit includes: (1) a superconducting component arranged in a multi-dimensional array of alternating narrow and wide portions, the superconducting component having an input terminal at a first end and an output terminal at a second end opposite of the first end; and (2) control circuitry coupled to the narrow portions of the superconducting component, the control circuitry configured to transition the narrow portions between superconducting and non-superconducting states.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting photon detectors. In one aspect, a photon detector includes: (1) a first waveguide configured to guide photons from a photon source; (2) a second waveguide that is distinct and separate from the first waveguide and optically-coupled to the first waveguide; and (3) a superconducting component positioned adjacent to the second waveguide and configured to detect photons within the second waveguide.

Abstract: A system includes a first superconducting wire and a second superconducting wire connected in parallel. The system includes a first current source coupled to the first superconducting wire and configured to supply a first current in response to a trigger event. The system includes a second current source coupled in series with the parallel combination of the first superconducting wire and the second superconducting wire and configured to supply a second current. The superconducting wires are configured to, while receiving the second current, operate in a superconducting state in the absence of the first current. The first superconducting wire is configured to, while receiving the second current, transition to a non-superconducting state in response to the first current. The second superconducting wire is configured to, while receiving the second current, transition to a non-superconducting state in response to the first superconducting wire transitioning to the non-superconducting state.

Abstract: An electronic device includes a first superconducting wire (with a first end and a second end) having a first threshold superconducting current. The device includes a second superconducting wire (with a first end and a second end) having a second threshold superconducting current that is less than the first threshold superconducting current. The second end of the first superconducting wire and the second end of the second superconducting wire are coupled to a common voltage node. A resistor is coupled between the first superconducting wire and the second superconducting wire, with a first end of the resistor coupled to the first end of the first superconducting wire and a second end of the resistor coupled to the first end of the second superconducting wire. The device includes a current source coupled with the first superconducting wire, and coupled with a combination of the resistor and the second superconducting wire.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating transistors. In one aspect, a transistor includes: (1) a semiconducting component configured to operate in an on state at temperatures above a semiconducting threshold temperature; and (2) a superconducting component configured to operate in a superconducting state while: (a) a temperature of the superconducting component is below a superconducting threshold temperature; and (b) a first current supplied to the superconducting component is below a current threshold; where: (i) the semiconducting component is located adjacent to the superconducting component; and (ii) 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 current exceeds the lowered current threshold, thereby transitioning the superconducting component to a non-superconducting state.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Superconducting nanowire avalanche photodetectors (SNAPs) have using meandering nanowires to detect incident photons. When a superconducting nanowire absorbs a photon, it switches from a superconducting state to a resistive state, producing a change in voltage that can be measured across the nanowire. A SNAP may include multiple nanowires in order to increase the fill factor of the SNAP's active area and the SNAP's detection efficiency. But using multiple meandering nanowires to achieve high fill-factor in SNAPs can lead to current crowding at bends in the nanowires. This current crowding degrades SNAP performance by decreasing the switching current, which the current at which the nanowire transitions from a superconducting state to a resistive state. Fortunately, staggering the bends in the nanowires reduces current crowding, increasing the nanowire switching current, which in turn increases the SNAP dynamic range.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting circuits. In one aspect, an electric circuit includes: (1) a first superconducting component having a first terminal, a second terminal, and a constriction region between the first terminal and the second terminal; (2) a second superconducting component having a third terminal and a fourth terminal; and (3) a first electrically-insulating component that thermally couples the first superconducting component and the second superconducting component such that heat produced at the constriction region is transferred through the first component to the second superconducting component.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting photon detectors. In one aspect, a photon detector includes: (1) a first waveguide configured to guide photons from a photon source; (2) a second waveguide that is distinct and separate from the first waveguide and optically-coupled to the first waveguide; and (3) a superconducting component positioned adjacent to the second waveguide and configured to detect photons within the second waveguide.

Abstract: An electronic device (e.g., a diode) is provided that includes a substrate and a patterned layer of superconducting material disposed over the substrate. The patterned layer forms a first electrode, a second electrode, and a loop coupling the first electrode with the second electrode by a first channel and a second channel. The first channel and the second channel have different minimum widths. The device further includes a magnet that applies a magnetic field to the loop, which produces an expulsion current in the loop that travels toward the second electrode in the first channel and toward the first electrode in the second channel. For a range of current magnitudes, when the magnetic field is applied to the patterned layer of superconducting material, the conductance from the first electrode to the second electrode is greater than the conductance from the second electrode to the first electrode.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting circuitry. In one aspect, an electronic system includes: (1) a first circuit that includes a plurality of superconducting wires connected in parallel with one another, the plurality of superconducting wires including: (a) a first superconducting wire with a corresponding first threshold superconducting current; and (b) a second superconducting wire; (2) a second circuit connected in parallel to the first circuit; (3) a first current source coupled to the first superconducting wire and configured to selectively supply a first current; and (4) a second current source coupled to a combination of the first circuit and the second circuit and configured to supply a second current such that the plurality of superconducting wires operate in a superconducting state; where a combination of the first current and the second current exceeds the first threshold superconducting current.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating photodetector circuitry. In one aspect, a photon detector system includes: (1) a first superconducting wire having a first threshold superconducting current; (2) a second superconducting wire having a second threshold superconducting current; (3) a resistor coupled to the first wire and the second wire; (4) current source(s) coupled to the first wire and configured to supply a current that is below the second threshold current; and (3) a second circuit coupled to the second wire. In response to receiving light at the first wire, the first wire transitions from a superconducting state to a non-superconducting state. In response to receiving light at the second wire while the first wire is in the non-superconducting state, the second wire transitions to a non-superconducting state, redirecting the first current to the second circuit.

Abstract: The various embodiments described herein include methods, devices, and systems for implementing logic gates. In one aspect, a circuit includes: (1) a superconducting component having a plurality of alternating narrow and wide portions; (2) a plurality of heat sources, each heat source of the plurality of heat sources coupled to a corresponding narrow portion of the plurality of alternating narrow and wide portions and configured to selectively provide heat to the corresponding narrow portion; (3) a bias current source coupled to each narrow portion of the plurality of alternating narrow and wide portions; and (4) an output node adapted to output a respective current while the plurality of superconducting components is in the non-superconducting state.

Abstract: The various embodiments described herein include methods, devices, and systems for implementing logic gates. In one aspect, a circuit includes: (1) superconducting components; (2) heat sources, each coupled to a corresponding superconducting component and configured to selectively provide heat to that component; and (3) a current source coupled to the superconducting components and configured to selectively provide: (a) a first current to bias the components such that combination of the first current and heat from any heat source causes the components to transition to a non-superconducting state; and (b) a second current to bias the components such that (i) combination of the second current and heat from each heat source causes the components to transition to the non-superconducting state, and (ii) a combination of the second current and heat from only a subset of the heat sources does not cause the components to transition to the non-superconducting state.

Abstract: A device includes a first semiconductor layer; a portion of a second semiconductor layer disposed on the first semiconductor layer; and a third semiconductor layer including a first region disposed on the portion of the second semiconductor layer and a second region disposed on the first semiconductor layer. A thickness of the first region is less than a predefined thickness. The device also includes an etch stop layer disposed on the third semiconductor layer; a plurality of distinct portions of a fourth semiconductor layer disposed on the etch stop layer and exposing one or more distinct portions of the etch stop layer over the portion of the second semiconductor layer; and a plurality of distinct portions of a superconducting layer disposed on the plurality of distinct portions of the fourth semiconductor layer and the exposed one or more distinct portions of the etch stop layer.

Abstract: The various embodiments described herein include methods, devices, and systems for fabricating and operating superconducting circuits. In one aspect, an electric circuit includes: (1) a first superconducting component having a first terminal, a second terminal, and a constriction region between the first terminal and the second terminal; (2) a second superconducting component having a third terminal and a fourth terminal; and (3) a first electrically-insulating component that thermally couples the first superconducting component and the second superconducting component such that heat produced at the constriction region is transferred through the first component to the second superconducting component.

Abstract: An electronic device (e.g., a diode) is provided that includes a substrate and a patterned layer of superconducting material disposed over the substrate. The patterned layer forms a first electrode, a second electrode, and a loop coupling the first electrode with the second electrode by a first channel and a second channel. The first channel and the second channel have different minimum widths. The device further includes a magnet that applies a magnetic field to the loop, which produces an expulsion current in the loop that travels toward the second electrode in the first channel and toward the first electrode in the second channel. For a range of current magnitudes, when the magnetic field is applied to the patterned layer of superconducting material, the conductance from the first electrode to the second electrode is greater than the conductance from the second electrode to the first electrode.