A microwave isolator device includes two nondegenerate microwave mixer devices, each mixer configured to receive a microwave input of an input frequency via a first port and to generate an idler signal of an idler frequency at a second port. The second ports of both mixers are coupled together. A first input/output (I/O) port is coupled to the first ports of the two mixers, and a second I/O port is also coupled to the first ports of the two mixers. A microwave signal (signal) communicated between the first I/O port and the second I/O port is transmitted while propagating in a first direction between the first I/O port to the second I/O port through the first mixer and the second mixer and to be blocked while propagating in a second direction between the second I/O port to the first I/O through the first mixer and the second 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 techniques for fabricating the same are provided. A superconducting device can comprise a first surface acoustic wave resonator comprising a first low-loss piezo-electric dielectric substrate. The superconducting device can also comprise a second surface acoustic wave resonator comprising a second low-loss piezo-electric dielectric substrate. Further, the superconducting device can comprise a Josephson ring modulator coupled to the first surface acoustic wave resonator and the second surface acoustic wave resonator. The Josephson ring modulator is 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 device for generating a qubit control signal includes: a first signal envelope generator circuit including a first multiple of signal sources, in which an output of each signal source of the first multiple of signal sources is combined to provide a first cumulative output; and a first mixer circuit coupled to the first signal envelope generator circuit, in which the first cumulative output is coupled to a first input of the first mixer circuit, and an output of the first mixer circuit includes a first qubit control signal.

An aspect includes one or more board layers. A first chip cavity is formed within the one or more board layers, wherein a first Josephson amplifier or Josephson mixer is disposed within the first chip cavity. The first Josephson amplifier or Josephson mixer comprises at least one port, each port connected to at least one connector disposed on at least one of the one or more board layers, wherein at least one of the one or more board layers comprises a circuit trace formed on the at least one of the one or more board layers.

An aspect includes one or more board layers. A first chip cavity is formed within the one or more board layers, wherein a first Josephson amplifier or Josephson mixer is disposed within the first chip cavity. The first Josephson amplifier or Josephson mixer comprises at least one port, each port connected to at least one connector disposed on at least one of the one or more board layers, wherein at least one of the one or more board layers comprises a circuit trace formed on the at least one of the one or more board layers.

A tunable dissipative circuit is presented for shifting a frequency of a radio frequency signal or microwave signal in a cryogenically cooled environment. One or more couplers make couplings between a propagation path and a tunable resonance element and a controllable dissipator element. A first control input to said tunable resonance element allows changing a resonance frequency of said tunable resonance element with a first control signal. A second control input to said controllable dissipator element allows changing a damping rate of said controllable dissipator element with a second control signal.

According to some aspects, a quantum circuit is provided including a plurality of non-linear circuit elements coupled together in series and in parallel, such that at least two of the circuit elements are coupled together in series and at least two of the circuit elements are coupled together in parallel, wherein the quantum circuit is configured to act as an amplifier.