Abstract: A superconducting input and/or output system employs at least one microwave superconducting resonator. The microwave superconducting resonator(s) may be communicatively coupled to a microwave transmission line. Each microwave superconducting resonator may include a first and a second DC SQUID, in series with one another and with an inductance (e.g., inductor), and a capacitance in parallel with the first and second DC SQUIDs and inductance. Respective inductive interfaces are operable to apply flux bias to control the DC SQUIDs. The second DC SQUID may be coupled to a Quantum Flux Parametron (QFP), for example as a final element in a shift register. A superconducting parallel plate capacitor structure and method of fabricating such are also taught.

Abstract: A superconducting circuit may include a transmission line having at least one transmission line inductance, a superconducting resonator, and a coupling capacitance that communicatively couples the superconducting resonator to the transmission line. The transmission line inductance may have a value selected to at least partially compensate for a variation in a characteristic impedance of the transmission line, the variation caused at least in part by the coupling capacitance. The coupling capacitance may be distributed along the length of the transmission line. A superconducting circuit may include a transmission line having at least one transmission line capacitance, a superconducting resonator, and a coupling inductance that communicatively couples the superconducting resonator to the transmission line. The transmission line capacitance may be selected to at least partially compensate for a variation in coupling strength between the superconducting resonator and the transmission line.

Abstract: Apparatus and methods advantageously provide parallel-plate capacitors in superconducting integrated circuits. A method may include forming a metal-oxide layer to overlie at least a portion of a first capacitor plate, the first capacitor plate comprising a superconductive material, and depositing a second capacitor plate to overlie at least a portion of the metal-oxide layer, the second capacitor plate comprising a superconductive material. The method may include depositing a base electrode of superconductive material to overlie at least a portion of a substrate, depositing the first capacitor plate to overlie at least a portion of the base electrode, and superconductingly electrically coupled to the base electrode, and depositing a counter electrode of superconductive material to overlie at least a portion of the second capacitor plate, the counter electrode superconductingly electrically coupled to the second capacitor plate.

Abstract: A device is dynamically isolated via a broadband switch that includes a plurality of cascade elements in series, wherein each cascade element comprises a first set of SQUIDs in series, a matching capacitor, and a second set of SQUIDs in series. The broadband switch is set to a passing state via flux bias lines during programming and readout of the device and set to a suppression state during device's calculation to reduce operation errors at the device. A device is electrically isolated from high-frequencies via an unbiased broadband switch. A device is coupled to a tunable thermal bath that includes a broadband switch.

Abstract: A superconducting input and/or output system employs at least one microwave superconducting resonator. The microwave superconducting resonator(s) may be communicatively coupled to a microwave transmission line. Each microwave superconducting resonator may include a first and a second DC SQUID, in series with one another and with an inductance (e.g., inductor), and a capacitance in parallel with the first and second DC SQUIDs and inductance. Respective inductive interfaces are operable to apply flux bias to control the DC SQUIDs. The second DC SQUID may be coupled to a Quantum Flux Parametron (QFP), for example as a final element in a shift register. A superconducting parallel plate capacitor structure and method of fabricating such are also taught.