Abstract: One or more systems, devices and/or methods of use provided herein relate to a device that can facilitate a process to measure a pair of spectral sidebands and suppress one of common mode phase or amplitude noise. A device can comprise an interferometer device that can detect an interference of two spectral sidebands. The interferometer device can comprise a signal circuit that can detect at least one of a phase or an amplitude of a signal resulting from the interference of the two spectral sidebands, an IQ modulator that can generate the two spectral sidebands using a portion of a local oscillator (LO) microwave signal and a pair of signals at a same intermediate frequency, and/or a mixer that can interfere the two spectral sidebands having been output or reflected from a device under test, including mixing the two spectral sidebands with another portion of the LO microwave signal.

Abstract: A qubit system for quantum computing includes a semiconductor structure, an array of plunger gates, and an array of magnetic structures. The array of gates is above the semiconductor structure forming a linear one-dimensional (1D) array of quantum dots (QDs) in the semiconductor structure. The array of magnetic structures generates stray fields in the same plane as the array of QDs. The QDs in the array are positioned between poles of individual magnetic structures in the array of magnetic structures. An external field is applied in a direction that is parallel to the linear 1D array of QDs. The external field is adjusted to allow the magnetization of the magnetic structure to create a stray field that leads to different total magnetic fields at different qubit locations.

Abstract: One or more systems, devices and/or methods of use provided herein relate to a device that can facilitate a process to measure a pair of spectral sidebands and suppress one of common mode phase or amplitude noise. A device can comprise an interferometer device that can detect an interference of two spectral sidebands. The interferometer device can comprise a signal circuit that can detect at least one of a phase or an amplitude of a signal resulting from the interference of the two spectral sidebands, an IQ modulator that can generate the two spectral sidebands using a portion of a local oscillator (LO) microwave signal and a pair of signals at a same intermediate frequency, and/or a mixer that can interfere the two spectral sidebands having been output or reflected from a device under test, including mixing the two spectral sidebands with another portion of the LO microwave signal.

Abstract: A surface acoustic wave resonator device comprises a substrate supporting: a gateable, electrically conducting layer; an interdigital transducer (IDT); a reflector grating that comprises a plurality of electrically separated fingers; a main ohmic contact; and a gate element. The IDT is configured to be connectable to a ground. The conducting layer is configured to be connectable to the ground via the main ohmic contact, while each of said fingers is electrically connected to a lateral side of the conducting layer. This defines a gateable channel, which extends from the fingers to the ground via the conducting layer and the main ohmic contact. The gate element is electrically insulated from the conducting layer. The gate element is configured to allow an electrical impedance of the gateable channel to be continuously tuned by applying a voltage bias to this gate element with respect to the ground, in operation of the device.

Abstract: A quantum processing comprises n fixed-frequency quantum circuits of distinct frequencies, where n?3. The device further comprises a frequency-tunable coupler, designed in such a manner that its frequency can be concomitantly modulated at m frequencies, where m?2, and wherein said m frequencies correspond, each, to a difference of energy between a respective pair of quantum states spanned by the quantum circuits. The quantum circuits are, each, coupled to the tunable coupler. The method may rely on modulating the frequency of the tunable coupler concomitantly at said m frequencies. This, for example, is done so as to drive m energy transitions between connected pairs of states spanned by the quantum circuits and achieve an entangled state of the quantum circuits as a superposition of l states spanned by the quantum circuits, l?m.

Abstract: A method of operating a quantum information processing apparatus is provided. This apparatus includes a structure of coupled qubits, where N?3, wherein the structure further includes coupling elements. The coupling elements couple pairs of N qubits, wherein, at least, a portion of the qubits are connected by a respective one of the coupling elements, whereby the two qubits of each said pair are connected by a respective coupling element. A method comprises identifying a path of M qubits in the structure of coupled qubits, wherein the path extends from a first qubit to a last qubit of the N qubits. The identified path consists of M qubits and M?1 coupling elements alternating along said path, where 2<M?N. A single-cycle operation is performed, wherein all pairs of two successive qubits in the identified path are concomitantly subjected to exchange-type interactions of distinct strengths.

Abstract: A method of operating a quantum information processing apparatus is provided. This apparatus includes a structure of coupled qubits, where N?3, wherein the structure further includes coupling elements. The coupling elements couple pairs of N qubits, wherein, at least, a portion of the qubits are connected by a respective one of the coupling elements, whereby the two qubits of each said pair are connected by a respective coupling element. A method comprises identifying a path of M qubits in the structure of coupled qubits, wherein the path extends from a first qubit to a last qubit of the N qubits. The identified path consists of M qubits and M?1 coupling elements alternating along said path, where 2<M?N. A single-cycle operation is performed, wherein all pairs of two successive qubits in the identified path are concomitantly subjected to exchange-type interactions of distinct strengths.

Abstract: Techniques relate to operating a quantum processing device is provided. The device includes at least two fixed-frequency quantum circuits coupled to a frequency-tunable coupler. The frequency of the coupler can be modulated so as to drive at least two selectively addressable energy transitions in the quantum processing device. The method includes modulating the frequency of the coupler so as to drive two first-order energy transitions. This is done so as to transfer (at least partly) an excitation of one of the quantum circuits to at least another one of the quantum circuits, via the tunable coupler. Related quantum processing devices are also provided.

Abstract: A surface acoustic wave resonator device comprises a substrate supporting: a gateable, electrically conducting layer; an interdigital transducer (IDT); a reflector grating that comprises a plurality of electrically separated fingers; a main ohmic contact; and a gate element. The IDT is configured to be connectable to a ground. The conducting layer is configured to be connectable to the ground via the main ohmic contact, while each of said fingers is electrically connected to a lateral side of the conducting layer. This defines a gateable channel, which extends from the fingers to the ground via the conducting layer and the main ohmic contact. The gate element is electrically insulated from the conducting layer. The gate element is configured to allow an electrical impedance of the gateable channel to be continuously tuned by applying a voltage bias to this gate element with respect to the ground, in operation of the device.

Abstract: A quantum processing comprises n fixed-frequency quantum circuits of distinct frequencies, where n?3. The device further comprises a frequency-tunable coupler, designed in such a manner that its frequency can be concomitantly modulated at m frequencies, where m?2, and wherein said m frequencies correspond, each, to a difference of energy between a respective pair of quantum states spanned by the quantum circuits. The quantum circuits are, each, coupled to the tunable coupler. The method may rely on modulating the frequency of the tunable coupler concomitantly at said m frequencies. This, for example, is done so as to drive m energy transitions between connected pairs of states spanned by the quantum circuits and achieve an entangled state of the quantum circuits as a superposition of l states spanned by the quantum circuits, l?m.

Abstract: A method for operating a quantum processing device is provided including at least two quantum circuits coupled to a tunable coupler, wherein the quantum circuits are subject to cross-talk, the method including: applying a primary signal to the quantum circuits so as to drive one or more energy transitions between states spanned by the quantum circuits; and applying a compensation signal to the tunable coupler, the compensation signal designed so as to shift at least one state spanned by the quantum circuits, in energy, to compensate for cross-talk between the quantum circuits. Related quantum processing devices and chips are also provided.

Abstract: Techniques relate to operating a quantum processing device is provided. The device includes at least two fixed-frequency quantum circuits coupled to a frequency-tunable coupler. The frequency of the coupler can be modulated so as to drive at least two selectively addressable energy transitions in the quantum processing device. The method includes modulating the frequency of the coupler so as to drive two first-order energy transitions. This is done so as to transfer (at least partly) an excitation of one of the quantum circuits to at least another one of the quantum circuits, via the tunable coupler. Related quantum processing devices are also provided.

Abstract: Techniques relate to operating a quantum processing device is provided. The device includes at least two fixed-frequency quantum circuits coupled to a frequency-tunable coupler. The frequency of the coupler can be modulated so as to drive at least two selectively addressable energy transitions in the quantum processing device. The method includes modulating the frequency of the coupler so as to drive two first-order energy transitions. This is done so as to transfer (at least partly) an excitation of one of the quantum circuits to at least another one of the quantum circuits, via the tunable coupler. Related quantum processing devices are also provided.