Superconducting device applications implemented with a surface acoustic wave resonator and a superconducting microwave resonator coupled to a Josephson ring modulator are provided. A method can comprise receiving, by a microwave Josephson mixer, and from a superconducting surface acoustic wave resonator of a superconducting device, a surface acoustic wave signal that comprises one or more phonons that resonate at a first frequency. The method can also comprise receiving, by the microwave Josephson mixer and from a superconducting microwave resonator of the superconducting device, a microwave signal that comprises one or more photons that can resonate at a second frequency. Further, the method can also comprise mixing, by the microwave Josephson mixer, the surface acoustic wave signal and the microwave signal based on a microwave control signal received from a microwave source operatively coupled to the microwave Josephson mixer.

Superconducting device applications implemented with a surface acoustic wave resonator and a superconducting microwave resonator coupled to a Josephson ring modulator are provided. A method can comprise receiving, by a microwave Josephson mixer, and from a superconducting surface acoustic wave resonator of a superconducting device, a surface acoustic wave signal that comprises one or more phonons that resonate at a first frequency. The method can also comprise receiving, by the microwave Josephson mixer and from a superconducting microwave resonator of the superconducting device, a microwave signal that comprises one or more photons that can resonate at a second frequency. Further, the method can also comprise mixing, by the microwave Josephson mixer, the surface acoustic wave signal and the microwave signal based on a microwave control signal received from a microwave source operatively coupled to the microwave Josephson mixer.

Superconducting device applications implemented with two surface acoustic wave resonators coupled to a Josephson ring modulator are provided. A method can include receiving, by a unitary Josephson mixer and from a first superconducting surface acoustic wave resonator of a superconducting device, a first surface acoustic wave signal that comprises one or more phonons that resonate at a first frequency, and receiving, by the unitary Josephson mixer and from a radio frequency source operatively coupled to the unitary Josephson mixer, a radio frequency control signal. The method can also include mixing the first surface acoustic wave signal and the radio frequency control signal and outputting a second surface acoustic wave signal based on mixing the first surface acoustic wave signal and the radio frequency control signal. The second surface acoustic wave signal can comprise one or more phonons that resonate at a second frequency.

A superconducting device that mixes surface acoustic waves and microwave signals and techniques for fabricating the same are provided. A superconducting device can comprise a superconducting surface acoustic wave resonator and a superconducting microwave resonator. The superconducting device can also comprise a Josephson ring modulator coupled to the superconducting surface acoustic wave resonator and the superconducting microwave resonator. The Josephson ring modulator can be a dispersive nonlinear three-wave mixing element.

A superconducting device that mixes surface acoustic waves and microwave signals and techniques for fabricating the same are provided. A superconducting device can comprise a superconducting surface acoustic wave resonator and a superconducting microwave resonator. The superconducting device can also comprise a Josephson ring modulator coupled to the superconducting surface acoustic wave resonator and the superconducting microwave resonator. The Josephson ring modulator can be a dispersive nonlinear three-wave mixing element.

A wireless Josephson-junction-based parametric converter is described. The converter may be formed on a substrate with antennas that pump are configured to wirelessly receive pump, signal and idler frequencies and couple the received frequencies to the converter's circuitry. Capacitors may also be fabricated on the same substrate and sized to tune operation of the converter to desired frequencies. The converter may be coupled directly to microwave waveguides, and may be tuned to different signal frequencies by applying magnetic flux to the converter circuitry.

A wireless Josephson-junction-based parametric converter is described. The converter may be formed on a substrate with antennas that pump are configured to wirelessly receive pump, signal and idler frequencies and couple the received frequencies to the converter's circuitry. Capacitors may also be fabricated on the same substrate and sized to tune operation of the converter to desired frequencies. The converter may be coupled directly to microwave waveguides, and may be tuned to different signal frequencies by applying magnetic flux to the converter circuitry.

A quantum computer hardware apparatus may include a first stage, which is connected to one or more signal generators, and a second stage adapted to be cooled down at a lower temperature than the first stage. Superconducting qubits are arranged in the second stage. The signal generators are configured, each, to generate radio frequency (RF) signals to drive the qubits, in operation. The apparatus may further include an intermediate stage between the first stage and the second stage, wherein the intermediate stage comprises one or more coolable filters, the latter configured for thermalizing RF signals from the signal generators. Related methods for thermalizing radio frequency signals in a quantum computer hardware apparatus are also disclosed.

A low-noise wide band amplifier is realized utilizing a superconductor-insulator-superconductor (SIS) junction, quasiparticle frequency mixers connected in tandem or in cascade, a first quasiparticle mixer performs first frequency mixing with use of a first local signal having a frequency not less than twice a frequency of an input signal to the first quasiparticle mixer, a second quasiparticle mixer performs second frequency mixing with use of a second local signal having a frequency not more than twice a frequency of an input signal to the second quasiparticle mixer, and signal amplification is performed through frequency conversion by extracting, from among a plurality of signals generated with the first and the second frequency mixing, a signal in a frequency band not more than a frequency band of the signal before the first frequency mixing and the second frequency mixing, using a transmission line or a filter.

A low-noise wide band amplifier is realized utilizing a superconductor-insulator-superconductor (SIS) junction, quasiparticle frequency mixers connected in tandem or in cascade, a first quasiparticle mixer performs first frequency mixing with use of a first local signal having a frequency not less than twice a frequency of an input signal to the first quasiparticle mixer, a second quasiparticle mixer performs second frequency mixing with use of a second local signal having a frequency not more than twice a frequency of an input signal to the second quasiparticle mixer, and signal amplification is performed through frequency conversion by extracting, from among a plurality of signals generated with the first and the second frequency mixing, a signal in a frequency band not more than a frequency band of the signal before the first frequency mixing and the second frequency mixing, using a transmission line or a filter.