Abstract: Embodiments of the present invention are directed to an integrated drive and readout circuit assembly. Directional couplers are configured to connect to qubit-resonator systems. Diplexers are coupled to the directional couplers. A microwave signal combiner is coupled to the diplexers.

Abstract: A Josephson parametric converter is provided. The Josephson parametric converter includes a multi-Josephson junction ring modulator having arrays of Josephson junctions arranged in a ring configuration with nodes inter-dispersed between the arrays. The Josephson parametric converter includes resonators formed from capacitors that shunt the multi-Josephson junction ring modulator and enable respective modes of the Josephson parametric converter.

Abstract: A technique relates to providing a superconducting quantum device. A fixed frequency transmon qubit is provided. A tunable frequency transmon qubit is provided. The fixed frequency transmon qubit is coupled to the tunable frequency transmon qubit to form a single qubit.

Abstract: A Josephson parametric converter is provided. The Josephson parametric converter includes a multi-Josephson junction ring modulator having arrays of N Josephson junctions arranged in a ring configuration with ring nodes inter-dispersed between the arrays. The multi-Josephson junction ring modulator further has a center node inter-connecting the ring nodes. N is an integer having a value greater than one. The Josephson parametric also includes a first and a second resonator formed from lumped-element capacitors that shunt the multi-Josephson junction ring modulator and respectively enable a first and a second mode of the Josephson parametric converter.

Abstract: A Josephson parametric converter is provided. The Josephson parametric converter includes a multi-Josephson junction ring modulator having arrays of N Josephson junctions arranged in a ring configuration with nodes inter-dispersed between the arrays. N is an integer having a value greater than one. The Josephson parametric converter includes a first and a second resonator formed from lumped-element capacitors that shunt the multi-Josephson junction ring modulator and respectively enable a first and a second mode of the Josephson parametric converter.

Abstract: A technique relates to a superconducting device. A gyrator includes a first mixing device coupled to a second mixing device. A lumped-element resistor is connected in parallel to the gyrator.

Abstract: A technique relates to operating a multimode Josephson parametric converter as a multimode quantum limited amplifier. The multimode Josephson parametric converter receives multiple quantum signals in parallel at different resonance frequencies. The multimode Josephson parametric converter amplifies simultaneously the multiple quantum signals, according to pump signals applied to the multimode Josephson parametric converter. The multiple quantum signals having been amplified at the different resonance frequencies are reflected, according to the pump signals.

Abstract: A technique relates to a router. The router includes a qubit signal distributor, a readout signal distributor, and diplexers communicatively coupled to the qubit signal distributor and the readout signal distributor.

Abstract: A Josephson parametric converter is provided. The Josephson parametric converter includes a multi-Josephson junction ring modulator having arrays of N Josephson junctions arranged in a ring configuration with nodes inter-dispersed between the arrays. N is an integer having a value greater than one. The Josephson parametric converter further includes a first and a second resonator formed from lumped-element capacitors that shunt the multi-Josephson junction ring modulator and respectively enable a first and a second mode of the Josephson parametric converter. The Josephson parametric converter also includes a first and a second LC circuit for respectively coupling the first and the second resonator to external feedlines.

Abstract: A technique relates to operating a multimode josephson parametric converter as a multimode quantum limited amplifier. The multimode. Josephson parametric converter receives multiple quantum signals in parallel at different resonance frequencies. The multimode Josephson parametric converter amplifies simultaneously the multiple quantum signals, according to pump signals applied to the multimode Josephson parametric converter. The multiple quantum signals having been amplified at the different resonance frequencies are reflected, according to the pump signals.

Abstract: A technique relates to a microwave device. A microwave system is configured to output a microwave readout signal, where the microwave system has an input and an output. An output microwave transmission line is connected to the output of the microwave system. A distributed Bragg reflector, integrated into a transmission line geometry, is configured as a low-loss infrared filter that blocks infrared radiation while allowing transmission of the microwave readout signal. The low-loss infrared filter is connected to the output microwave transmission line.

Abstract: A technique relates to configuring a superconducting router. The superconducting router is operated in a first mode. Ports are configured to be in reflection in the first mode in order to reflect a signal. The superconducting router is operated in a second mode. A given pair of the ports is connected together and in transmission in the second mode, such that the signal is permitted to pass between the given pair of the ports.

Abstract: A technique relates to a lossless microwave switch discussed herein. Multiple ports are included in the lossless microwave switch. Tunable filters are included in the lossless microwave switch. Each of the ports is operatively coupled a corresponding one of the tunable filters.

Abstract: A technique relates to a superconducting microwave device. A left-handed resonator include at least one unit cell. A non-linear dispersive medium is connected to the left-handed resonator, such that one end of the left-handed resonator is connected to the non-linear dispersive medium and an opposite end of the left-handed resonator is connected to a port. The left-handed resonator and the non-linear dispersive medium are configured to output a quantum signal in a squeezed state.

Abstract: A technique relates to a microwave device. A pump resonator, at a first pump resonator end, is connected to both a dispersive nonlinear element and a first stub. The pump resonator, at a second pump resonator end, is capacitively coupled to a pump port, where the first stub is terminated in an open circuit. A quantum signal resonator, at a first quantum signal resonator end, is connected to both the dispersive nonlinear element and a second stub. The quantum signal resonator, at a second signal resonator end, is capacitively coupled to a signal port, where the second stub is connected to ground.

Abstract: A technique relates to a circuit for a sum frequency generator. A first resonator is connected to a Josephson ring modulator (JRM), and the first resonator is configured to receive a first photon at a first frequency. A second resonator is connected to the JRM, and the second resonator is configured to have a first harmonic and no second harmonic. The second resonator is configured to receive a second photon at a second frequency, and the first resonator is configured to output an up-converted photon. The up-converted photon has an up-converted frequency that is a sum of the first frequency and the second frequency.

Abstract: A technique relates to a qubit readout system. A cavity-qubit system has a qubit and a readout resonator and outputs a readout signal. A lossless superconducting circulator is configured to receive the microwave readout signal from the cavity-qubit system and transmit the microwave readout signal according to a rotation. A quantum limited directional amplifier amplifies the readout signal. A directional coupler is connected to and biases the amplifier to set a working point. A microwave bandpass filter transmits in a microwave frequency band by passing the readout signal while blocking electromagnetic radiation outside of the microwave frequency band. A low-loss infrared filter has a distributed Bragg reflector integrated into a transmission line. The low-loss filter is configured to block infrared electromagnetic radiation while passing the microwave readout signal. The low-loss infrared filter is connected to the microwave bandpass filter to receive input of the microwave readout signal.

Abstract: A technique relates to a microwave detection device. A quantum non-demolition microwave photon detector is connected to a quadrature microwave hybrid coupler connected. A dispersive nonlinear element is coupled to the quadrature microwave hybrid coupler.

Abstract: A technique relates to a microwave device. A pump resonator, at a first pump resonator end, is connected to both a dispersive nonlinear element and a first stub. The pump resonator, at a second pump resonator end, is capacitively coupled to a pump port, where the first stub is terminated in an open circuit. A quantum signal resonator, at a first quantum signal resonator end, is connected to both the dispersive nonlinear element and a second stub. The quantum signal resonator, at a second signal resonator end, is capacitively coupled to a signal port, where the second stub is connected to ground.

Abstract: A technique relates to a qubit readout system. A cavity-qubit system has a qubit and a readout resonator and outputs a readout signal. A lossless superconducting circulator is configured to receive the microwave readout signal from the cavity-qubit system and transmit the microwave readout signal according to a rotation. A quantum limited directional amplifier amplifies the readout signal. A directional coupler is connected to and biases the amplifier to set a working point. A microwave bandpass filter transmits in a microwave frequency band by passing the readout signal while blocking electromagnetic radiation outside of the microwave frequency band. A low-loss infrared filter has a distributed Bragg reflector integrated into a transmission line. The low-loss filter is configured to block infrared electromagnetic radiation while passing the microwave readout signal. The low-loss infrared filter is connected to the microwave bandpass filter to receive input of the microwave readout signal.