Abstract: A tunable superconducting circuit includes a first charge island, a second charge island, a third charge island, a fourth charge island, a first junction loop electrically coupled to the first and third charge islands, a second junction loop coupled to the second and third charge islands and a third junction loop coupled to the third and fourth charge islands, wherein the first, second and third junction loops are tuned in frequency to operate together as a qubit.

Abstract: A device includes a housing, at least two qubits disposed in the housing and a resonator disposed in the housing and coupled to the at least two qubits, wherein the at least two qubits are maintained at a fixed frequency and are statically coupled to one another via the resonator, wherein energy levels |03> and |12> are closely aligned, wherein a tuned microwave signal applied to the qubit activates a two-qubit phase interaction.

Abstract: A device includes a housing, at least two qubits disposed in the housing and a resonator disposed in the housing and coupled to the at least two qubits, wherein the at least two qubits are maintained at a fixed frequency and are statically coupled to one another via the resonator, wherein energy levels |03> and |12> are closely aligned, wherein a tuned microwave signal applied to the qubit activates a two-qubit phase interaction.

Abstract: A quantum electronic circuit device includes a housing having an internal resonant cavity, a qubit disposed within a volume of the internal resonant cavity and a non-superconducting metallic material mechanically and thermally coupled to the qubit within the internal resonant cavity and contiguously extending to the exterior of the housing.

Abstract: A device includes a housing, at least two qubits disposed in the housing and a resonator disposed in the housing and coupled to the at least two qubits, wherein the at least two qubits are maintained at a fixed frequency and are statically coupled to one another via the resonator, wherein energy levels |03> and |12> are closely aligned, wherein a tuned microwave signal applied to the qubit activates a two-qubit phase interaction.

Abstract: A method of characterizing a tunable superconducting circuit, includes selecting an operating direct current (DC) flux for a first charge island from a plurality of coupled charge islands residing in the tunable superconducting circuit coupled to a first resonator and a second resonator, tuning operating DC flux values for at least two charge islands from the plurality of coupled charge islands, measuring coupling energies of the first resonator and the second resonator and measuring frequencies from each of the plurality of coupled charge islands.

Abstract: A device includes a volume bounded by electromagnetically conducting walls, an aperture in a bounding wall of the electromagnetically conducting walls, a plurality of quantum systems disposed within the volume and an electromagnetic field source coupled to the volume via the aperture.

Abstract: A quantum electronic circuit device includes a housing having an internal resonant cavity, a qubit disposed within a volume of the internal resonant cavity and a non-superconducting metallic material mechanically and thermally coupled to the qubit within the internal resonant cavity and contiguously extending to the exterior of the housing.

Abstract: Low-loss superconducting devices and methods for fabricating low loss superconducting devices. For example, superconducting devices, such as superconducting resonator devices, are formed with a (200)-oriented texture titanium nitride (TiN) layer to provide high Q, low loss resonator structures particularly suitable for application to radio-frequency (RF) and/or microwave superconducting resonators, such as coplanar waveguide superconducting resonators. In one aspect, a method of forming a superconducting device includes foaming a silicon nitride (SiN) seed layer on a substrate, and forming a (200)-oriented texture titanium nitride (TiN) layer on the SiN seed layer.

Abstract: A quantum information processing system includes a first composite quantum system, a second composite quantum system, a plurality of electromagnetic field sources coupled to the system and an adjustable electromagnetic coupling between the first composite quantum system and the second composite quantum system.

Abstract: A quantum information processing system includes a first composite quantum system, a second composite quantum system, a plurality of electromagnetic field sources coupled to the system and an adjustable electromagnetic coupling between the first composite quantum system and the second composite quantum system.

Abstract: A device includes a volume bounded by electromagnetically conducting walls, an aperture in a bounding wall of the electromagnetically conducting walls, a plurality of quantum systems disposed within the volume and an electromagnetic field source coupled to the volume via the aperture.

Abstract: A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Abstract: An apparatus for measuring component performance including a feed line having an input port and an output port, a first resonator connected to the feed line, a first Josephson junction device connected to the first resonator and to ground, and a second resonator connected to the feed line and to ground.

Abstract: A method for measuring the quantum state of a resonator includes, exciting an input port of a circuit with signal, measuring a phase shift of the signal at an output port of the circuit, wherein the resonator is coupled to the input and the output ports, and calculating a quantum state of the resonator as a function of the measured phase shift of the signal.

Abstract: A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Abstract: A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.

Abstract: A method for measuring the quantum state of a resonator includes, exciting an input port of a circuit with signal, measuring a phase shift of the signal at an output port of the circuit, wherein the resonator is coupled to the input and the output ports, and calculating a quantum state of the resonator as a function of the measured phase shift of the signal.

Abstract: An apparatus for measuring component performance including a feed line having an input port and an output port, a first resonator connected to the feed line, and a first Josephson junction device connected to the first resonator and to ground.

Abstract: A method for determining whether a quantum system comprising a superconducting qubit is occupying a first basis state or a second basis state once a measurement is performed is provided. The method, comprising: applying a signal having a frequency through a transmission line coupled to the superconducting qubit characterized by two distinct, separate, and stable states of differing resonance frequencies each corresponding to the occupation of the first or second basis state prior to measurement; and measuring at least one of an output power or phase at an output port of the transmission line, wherein the measured output power or phase is indicative of whether the superconducting qubit is occupying the first basis state or the second basis state.