A qubit system is provided wherein successive sets of M RF pulses are generated simultaneously, for application to qubit circuits in a plurality of N groups of M qubit circuits. M switching multiplexer circuits are used, each to pass a respective one of the M RF pulses in the set to a selected one of a plurality of N M to one RF combiners in a multiplexing mode. Combined RF pulses at M different RF frequencies are transmitted from each of the N combiners to a transmission structure for a respective one of the groups. Individual ones of the combined RF pulses are coupled from the transmission structure for the group to respective ones of the qubit circuits of the groups via respective frequency selective filters. In a broadcast mode the M switching multiplexer circuits are used to transmit the simultaneous pulses to all of RF combiners.

A method for generating a voltage waveform includes providing an optical signal, which comprises one or more sequences of optical pulses, distributing the optical pulses via optical waveguides to a plurality of optical-to-electrical converter units, using the optical-to-electrical converter units to convert the optical pulses into electric driving current pulses, generating voltage pulses by driving Josephson junctions with the electric driving current pulses.

A system comprises pulse generation and measurement circuitry comprising a plurality of pulse generator circuits and a plurality of ports, and management circuitry. The management circuitry is operable to analyze a specification of a controlled system and controlled elements that comprises a definition of a controlled element of the control system, and a definition of one or more pulses available for transmission by the control system. The management circuitry is operable to configure, based on the specification, the pulse generation and measurement circuitry to: generate the one or more pulses via one or more of the plurality of pulse generator circuits; and output the one or more pulses to the controlled element via one or more of the plurality of ports.

A system comprises pulse generation and measurement circuitry comprising a plurality of pulse generator circuits and a plurality of ports, and management circuitry. The management circuitry is operable to analyze a specification of a controlled system and controlled elements that comprises a definition of a controlled element of the control system, and a definition of one or more pulses available for transmission by the control system. The management circuitry is operable to configure, based on the specification, the pulse generation and measurement circuitry to: generate the one or more pulses via one or more of the plurality of pulse generator circuits; and output the one or more pulses to the controlled element via one or more of the plurality of ports.

One example describes a superconducting XOR-gate system. The system includes a pulse generator configured to generate a decision pulse. The system also includes an input superconducting XOR-2 gate that receives a first superconducting logic input signal and a second superconducting logic input signal and is configured to perform a logic XOR function based on the decision pulse on a given phase of a clock signal to provide an intermediate superconducting logic output signal. The system also includes an output superconducting XOR-2 gate that receives the intermediate superconducting logic output signal and a third superconducting logic input signal and is configured to perform a logic XOR function based on the decision pulse on the given phase of the clock signal to provide a superconducting logic output signal.

One example describes a superconducting XOR-gate system. The system includes a pulse generator configured to generate a decision pulse. The system also includes an input superconducting XOR-2 gate that receives a first superconducting logic input signal and a second superconducting logic input signal and is configured to perform a logic XOR function based on the decision pulse on a given phase of a clock signal to provide an intermediate superconducting logic output signal. The system also includes an output superconducting XOR-2 gate that receives the intermediate superconducting logic output signal and a third superconducting logic input signal and is configured to perform a logic XOR function based on the decision pulse on the given phase of the clock signal to provide a superconducting logic output signal.

Analog processors for solving various computational problems are provided. Such analog processors comprise a plurality of quantum devices, arranged in a lattice, together with a plurality of coupling devices. The analog processors further comprise bias control systems each configured to apply a local effective bias on a corresponding quantum device. A set of coupling devices in the plurality of coupling devices is configured to couple nearest-neighbor quantum devices in the lattice. Another set of coupling devices is configured to couple next-nearest neighbor quantum devices. The analog processors further comprise a plurality of coupling control systems each configured to tune the coupling value of a corresponding coupling device in the plurality of coupling devices to a coupling. Such quantum processors further comprise a set of readout devices each configured to measure the information from a corresponding quantum device in the plurality of quantum devices.

Analog processors for solving various computational problems are provided. Such analog processors comprise a plurality of quantum devices, arranged in a lattice, together with a plurality of coupling devices. The analog processors further comprise bias control systems each configured to apply a local effective bias on a corresponding quantum device. A set of coupling devices in the plurality of coupling devices is configured to couple nearest-neighbor quantum devices in the lattice. Another set of coupling devices is configured to couple next-nearest neighbor quantum devices. The analog processors further comprise a plurality of coupling control systems each configured to tune the coupling value of a corresponding coupling device in the plurality of coupling devices to a coupling. Such quantum processors further comprise a set of readout devices each configured to measure the information from a corresponding quantum device in the plurality of quantum devices.

One example includes an isochronous receiver system. The system includes a pulse receiver configured to receive an input data signal from a transmission line and to convert the input data signal to a pulse signal. The system also includes a converter system comprising a phase converter system. The phase converter system includes a plurality of pulse converters associated with a respective plurality of sampling windows across a period of an AC clock signal. At least two of the sampling windows overlap at any given phase of the AC clock signal, such that the converter system is configured to generate an output pulse signal that is phase-aligned with at least one of a plurality of sampling phases of the AC clock signal based on associating the pulse signal with at least two of the sampling windows.

Systems and techniques that facilitate entanglement via driving dark modes are provided. In various embodiments, a method can comprise accessing a first multi-mode qubit and a second multi-mode qubit. In various cases, the first multi-mode qubit can be coupled to the second multi-mode qubit by a mode-selective coupler. In various aspects, the method can further comprise exciting a dark mode of the first multi-mode qubit. In various cases, the exciting the dark mode can entangle the first multi-mode qubit with the second multi-mode qubit.