Abstract: A superconducting circuit includes a photon detector component, a second component, and a multi-taper superconducting connector shaped to reduce current crowding, the superconducting connector electrically connecting the photon detector component and the second component. The multi-taper superconducting connector includes a first taper arranged adjacent the photon detector component and a second taper arranged adjacent the second component.

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. In some implementations, the superconducting component and the control circuitry are formed on different layers of the programmable circuit.

Abstract: A programmable circuit includes a superconducting multi-dimensional array. The programmable circuit further includes a plurality of photon detectors coupled to respective portions of the superconducting multi-dimensional array, each photon detector configured to selectively provide input to a corresponding respective portion sufficient to transition the corresponding respective portion from a superconducting state to a non-superconducting state. The programmable circuit also includes one or more electrical terminals coupled to respective second portions of the superconducting multi-dimensional array.

Abstract: A device includes a superconductor layer and a piezoelectric layer positioned adjacent to the superconductor layer. The piezoelectric layer is configured to apply a first strain to the superconductor layer in response to receiving a first voltage that is below a predefined voltage threshold and to apply a second strain to the superconductor layer in response to receiving a second voltage that is above the predefined voltage threshold. While the device is maintained below a superconducting threshold temperature for the superconductor layer and is supplied with current below a superconducting threshold current for the superconductor layer, the superconductor layer is configured to 1) operate in a superconducting state when the piezoelectric layer applies the first strain to the superconductor layer and 2) operate in an insulating state when the piezoelectric layer applies the second strain to the superconductor layer.

Abstract: A superconducting circuit includes a first component having a first connection point. The first connection point has a first width. The superconducting circuit includes a second component having a second connection point. The second connection point has a second width that is larger than the first width. The superconducting circuit includes a superconducting connector shaped to reduce current crowding. The superconducting connector electrically connects the first connection point and the second connection point. The superconducting connector includes a first taper positioned adjacent the first connection point and having a non-linear shape and a second taper positioned adjacent the second connection point.

Abstract: A programmable circuit includes a superconducting component arranged in a multi-dimensional array of alternating narrow and wide portions. The programmable circuit further includes a plurality of heat sources, each heat source configured to selectively provide heat to a respective narrow portion sufficient to transition the respective narrow portion from a superconducting state to a non-superconducting state. The programmable circuit further includes a plurality of electrical terminals, each electrical terminal coupled to a respective wide portion of the multi-dimensional array.

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 diodes. In one aspect, an electrical circuit includes: (1) a diode component having a particular energy band gap; (2) an electrical source electrically coupled to the diode component and configured to bias the diode component in a particular state; and (3) a heating component thermally coupled to a junction of the diode component and configured to selectively supply heat corresponding to the particular energy band gap.

Abstract: An electronic component having an asymmetric impedance is provided. The component includes first, second and third branches that connect at a common node. The component includes a first portion of superconducting material disposed along the first branch and a second portion of superconducting material disposed along the second branch. The component includes a first device disposed along the first branch and configured to transition the second portion of the superconducting material to a non-superconducting state when a current between a first terminal of the first device and a second terminal of the first device exceeds a first threshold value and a second device disposed along the second branch and configured to transition the first portion of the superconducting material to a non-superconducting state when a current between a first terminal of the second device and a second terminal of the second device exceeds a second threshold value.

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. In some implementations, the superconducting component and the control circuitry are formed on different layers of the programmable circuit.

Abstract: An electric circuit includes one or more photon detector components and a superconducting logic gate component coupled to respective outputs of the one or more photon detector components. The electric circuit further includes a bias source electrically coupled to the superconducting logic gate component, the bias source configured to provide a bias current adapted to cause the superconducting logic gate component to function as a logical gate. The electric circuit also includes an optical switch component electrically coupled to an output of the superconducting logic gate component.

Abstract: The various embodiments described herein include methods for manufacturing superconductor devices. In some embodiments, a method of manufacturing a superconductor includes: (1) manufacturing a first superconductor device; (2) characterizing the first superconductor device, including: (a) obtaining x-ray diffraction spectra of the first superconductor device; and (b) identifying a ratio of a first cubic phase peak to a second cubic phase peak in the x-ray diffraction spectra; (3) adjusting a manufacturing parameter based on the identified ratio; and (4) manufacturing a second superconductor device with the adjusted manufacturing parameter.

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. For a range of current magnitudes, when a 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 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 method of resolving a number of photons received by a photon detector includes optically coupling a waveguide to a superconducting wire having alternating narrow and wide portions; electrically coupling the superconducting wire to a current source; and electrically coupling an electrical contact in parallel with the superconducting wire. The electrical contact has a resistance less than a resistance of the superconducting wire while at least one narrow portion of the superconducting wire is in a non-superconducting state. The method includes providing to the superconducting wire, from the current source, a current configured to maintain the superconducting wire in a superconducting state in the absence of incident photons; receiving one or more photons via the waveguide; measuring an electrical property of the superconducting wire, proportional to a number of photons incident on the superconducting wire; and determining the number of received photons based on the electrical property.

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: A programmable circuit includes a superconducting component arranged in a multi-dimensional array of alternating narrow and wide portions. The programmable circuit further includes a plurality of heat sources, each heat source configured to selectively provide heat to a respective narrow portion sufficient to transition the respective narrow portion from a superconducting state to a non-superconducting state. The programmable circuit further includes a plurality of electrical terminals, each electrical terminal coupled to a respective wide portion of the multi-dimensional array.

Abstract: A device includes a substrate, a dielectric layer on the substrate, a waveguide within the dielectric layer, and a photodetector optically coupled to the waveguide. The photodetector is disposed above the waveguide layer and is monolithically integrated with the substrate. The photodetector is configured to operate at low temperatures, such as below about 50 K or about 20 K. In some embodiments, the monolithic photonic device includes thermal isolation structures and optical isolation structures. Techniques for manufacturing the monolithic photonic device, including the thermal isolation structures and optical isolation structures, are also described.

Abstract: A method of resolving a number of photons received by a photon detector includes optically coupling a waveguide to a superconducting wire having alternating narrow and wide portions; electrically coupling the superconducting wire to a current source; and electrically coupling an electrical contact in parallel with the superconducting wire. The electrical contact has a resistance less than a resistance of the superconducting wire while at least one narrow portion of the superconducting wire is in a non-superconducting state. The method includes providing to the superconducting wire, from the current source, a current configured to maintain the superconducting wire in a superconducting state in the absence of incident photons; receiving one or more photons via the waveguide; measuring an electrical property of the superconducting wire, proportional to a number of photons incident on the superconducting wire; and determining the number of received photons based on the electrical property.

Abstract: An electric circuit includes a plurality of superconducting components, each of the plurality of superconducting components having: a respective first terminal; a respective second terminal; and a respective input. The electric circuit further includes a bias current source electrically-connected to the respective first terminal of each of the plurality of superconducting components. The bias current source is configured to provide a bias current adapted to cause the electric circuit to function as a logical OR gate on the respective inputs of the plurality of superconducting components. The electric circuit further includes an output node adapted to output a state of the logical OR gate.