Abstract: A control arrangement is disclosed for providing a plurality of phase-coherent oscillating signals. It comprises a reference clock signal arrangement for providing a high-frequency reference clock signal and a plurality of modules each comprising a plurality of channels for providing the plurality of phase-coherent oscillating signals.

Abstract: An arrangement, an apparatus, a quantum computing system, and a method are disclosed for reducing qubit leakage errors. In an example, an apparatus includes a qubit having a ground state and a plurality of excited states. The plurality of excited states include a lowest excited state. An energy difference between the ground state and the lowest excited state corresponds to a first frequency, and an energy difference between the lowest excited state and another excited state in the plurality of excited states corresponds to a second frequency. The apparatus also includes an energy dissipation structure to dissipate transferred energy, and a filter having a stopband and a passband. The filter is coupled to the qubit and to the energy dissipation structure. The stopband includes the first frequency and the passband includes the second frequency for reducing qubit leakage errors.

Abstract: An arrangement, an apparatus, a quantum computing system, and a method are disclosed for reducing qubit leakage errors. In an example, an apparatus includes a qubit having a ground state and a plurality of excited states. The plurality of excited states include a lowest excited state. An energy difference between the ground state and the lowest excited state corresponds to a first frequency, and an energy difference between the lowest excited state and another excited state in the plurality of excited states corresponds to a second frequency. The apparatus also includes an energy dissipation structure to dissipate transferred energy, and a filter having a stopband and a passband. The filter is coupled to the qubit and to the energy dissipation structure. The stopband includes the first frequency and the passband includes the second frequency for reducing qubit leakage errors.

Abstract: An arrangement, an apparatus, a quantum computing system, and a method are disclosed for reducing qubit leakage errors. In an example, an apparatus includes a qubit having a ground state and a plurality of excited states. The plurality of excited states include a lowest excited state. An energy difference between the ground state and the lowest excited state corresponds to a first frequency, and an energy difference between the lowest excited state and another excited state in the plurality of excited states corresponds to a second frequency. The apparatus also includes an energy dissipation structure to dissipate transferred energy, and a filter having a stopband and a passband. The filter is coupled to the qubit and to the energy dissipation structure. The stopband includes the first frequency and the passband includes the second frequency for reducing qubit leakage errors.

Abstract: A quantum computing system, a method, a computer program, and an arrangement for selectively shifting qubit resonance frequencies are disclosed herein. According to an embodiment, an arrangement for selectively shifting qubit resonance frequencies in a quantum computing system comprises a plurality of qubits including at least a first qubit and a second qubit, and a plurality of coupling control resonators including at least a first coupling control resonator and a second coupling control resonator. The arrangement also includes a coupling control signal line. The first coupling control resonator may be configured to shift the resonance frequency of the first qubit when the coupling control signal includes a frequency component in the resonance frequency band of the first coupling control resonator.

Abstract: A cryogenic integrated circuit or integrated module includes a travelling wave parametric amplifier or a Josephson parametric amplifier. The cryogenic integrated circuit or integrated module also includes an oscillator, a signal input, a biasing input, and a signal output. The oscillator is connected to an input of the amplifier and is configured to produce an oscillating drive signal. The signal input couples input signals into the amplifier. The biasing input couples biasing signals into the oscillator. The signal output conveys output signals from the amplifier out of the cryogenic integrated circuit or integrated module.