Abstract: Some aspects are directed to a method of operating a circuit quantum electrodynamics system that includes a physical qubit dispersively coupled to a quantum mechanical oscillator, the method comprising applying a first drive waveform to the quantum mechanical oscillator, and applying a second drive waveform to the physical qubit concurrent with the application of the first drive waveform, wherein the first and second drive waveforms are configured to produce a state transition of the circuit quantum electrodynamics system from an initial state to a final state.

Abstract: According to some aspects, a waveform processor is provided for control of quantum mechanical systems. Some embodiments of the waveform processor may be used to control quantum systems used in quantum computation, such as qubits. According to some embodiments, a waveform processor may include a first sequencer configured to sequentially execute master instructions according to a defined order and output digital values in response to the executed master instructions, and a second sequencer coupled to the first sequencer and configured to generate analog waveforms at least in part by transforming digital waveforms according to digital values received from the first sequencer. The analog waveforms may be applied to a quantum system. In some embodiments, the waveform processor may further include a waveform analyzer configured to integrate analog waveforms received from a quantum system and output results of said integration to the first sequencer.

Abstract: According to some aspects, a method is provided of operating a system that includes a multi-level quantum system dispersively coupled to a first quantum mechanical oscillator and dispersively coupled to a second quantum mechanical oscillator, the method comprising applying a first drive waveform to the multi-level quantum system, applying one or more second drive waveforms to the first quantum mechanical oscillator, and applying one or more third drive waveforms to the second quantum mechanical oscillator.

Abstract: A wireless Josephson-junction-based amplifier is described that provides improved tunability and increased control over both a quality factor Q and participation ratio p of the amplifier. The device may be fabricated on a chip and mounted in a waveguide. No wire bonding between the amplifier and coaxial cables or a printed circuit board is needed. At least one antenna on the chip may be used to couple energy between the waveguide and wireless JBA. The amplifier is capable of gains greater than 25 dB.

Abstract: 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.

Abstract: A wireless Josephson-junction-based amplifier is described that provides improved tunability and increased control over both a quality factor Q and participation ratio p of the amplifier. The device may be fabricated on a chip and mounted in a waveguide. No wire bonding between the amplifier and coaxial cables or a printed circuit board is needed. At least one antenna on the chip may be used to couple energy between the waveguide and wireless JBA. The amplifier is capable of gains greater than 25 dB.

Abstract: According to some aspects, a quantum mechanical system is provided, comprising a resonator having a plurality of superconducting surfaces and configured to support at least one electromagnetic oscillation mode within a three-dimensional region, wherein the plurality of superconducting surfaces include a first superconducting surface that defines a first plane, and a physical qubit comprising at least one planar component that is planar within the first plane and borders the three-dimensional region.

Abstract: 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.

Abstract: According to some aspects, a circuit is provided comprising a plurality of Josephson junctions arranged in series in a loop, at least one magnetic element producing magnetic flux through the loop, a plurality of superconducting resonators, each resonator coupled to the loop between a different neighboring pair of Josephson junctions of the plurality of Josephson junctions, a plurality of ports, each port coupled to at least one of the plurality of resonators at ends of the resonators opposite to ends at which the resonators are coupled to the loop, and at least one controller configured to provide input energy to each of the plurality of ports that causes the circuit to function as a circulator between the plurality of ports.

Abstract: A low-noise directional amplifier includes a first port, a second port, a first coupler and a second coupler. The first port is coupled to a first coupler. The low-noise directional amplifier also includes at least two phase preserving amplifiers, a first phase preserving amplifier connected to the first coupler and a second coupler, and the second phase preserving amplifier connected to the first coupler and the second coupler.

Abstract: Some embodiments are directed to a device including multiple substrates comprising one or more troughs. The substrates are disposed such that the one or more troughs form at least one enclosure. At least one superconducting layer covers at least portion of the at least one enclosure. Other embodiments are directed to a method for manufacturing a superconducting device. The method includes acts of forming at least one trough in at least a first substrate; covering at least a portion of the first substrate with a superconducting material; covering at least a portion of a second substrate with the superconducting material; and bonding the first substrate and the second substrate to form at least one enclosure comprising the at least one trough and the superconducting material.

Abstract: Some embodiments are directed to a device including multiple substrates comprising one or more troughs. The substrates are disposed such that the one or more troughs form at least one enclosure. At least one superconducting layer covers at least a portion of the at least one enclosure. Other embodiments are directed to a method for manufacturing a superconducting device. The method includes acts of forming at least one trough in at least a first substrate; covering at least a portion of the first substrate with a superconducting material; covering at least a portion of a second substrate with the superconducting material; and bonding the first substrate and the second substrate to form at least one enclosure comprising the at least one trough and the superconducting material.

Abstract: A wireless Josephson-junction-based amplifier is described that provides improved tunability and increased control over both a quality factor Q and participation ratio p of the amplifier. The device may be fabricated on a chip and mounted in a waveguide. No wire bonding between the amplifier and coaxial cables or a printed circuit board is needed. At least one antenna on the chip may be used to couple energy between the waveguide and wireless JBA. The amplifier is capable of gains greater than 25 dB.