Abstract: A device comprises a first superconducting quantum bit, a second superconducting quantum bit, and a coupler circuit. The first superconducting quantum bit comprises a superconducting tunnel junction and a shunt inductor which form a first superconducting loop. The second superconducting quantum bit comprises a superconducting tunnel junction and a shunt inductor which form a second superconducting loop. The coupler circuit is coupled between the first and second superconducting quantum bits. The coupler circuit is configured to implement an entanglement gate operation between the first and second superconducting quantum bits through exchange interactions between the coupler circuit and the first superconducting quantum bit and the second superconducting quantum bit, when the coupler circuit is driven by a control signal.

Abstract: A device comprises a data quantum bit, a first quantum bit coupler, a second quantum bit coupler, and an auxiliary quantum bit. The first quantum bit coupler is coupled to the data quantum bit. The second quantum bit coupler is coupled to the first quantum bit coupler. The auxiliary quantum bit is coupled to the second quantum bit coupler. The first quantum bit coupler is configured to operate in a state to suppress interaction between the data quantum bit and the auxiliary quantum bit. The first quantum bit coupler and the second quantum bit coupler are each configured to operate in a respective state to enable interaction between the data quantum bit and the auxiliary quantum bit and entangle a state of the data quantum bit with a state of the auxiliary quantum bit.

Abstract: A device comprises first and second superconducting quantum bits, and a multimode coupler circuit coupled between the first and second superconducting quantum bits. The multimode coupler circuit comprises a first mode and a second mode, and is configured to operate in one of a first state and a second state, in response to a flux tuning control signal. In the first state, the first superconducting quantum bit is exchange coupled to the first mode, and the second superconducting quantum bit is exchange coupled to the second mode, to suppress interaction between the first and second superconducting quantum bits. In the second state, the first and second superconducting quantum bits are exchange coupled to both the first and second modes, to enable an interaction between the first and second superconducting quantum bits and perform an entanglement gate operation.

Abstract: Techniques and couplers for managing coupling between qubits are presented. A first tuneable coupler qubit (TCQ) can comprise a first frequency mode and a second frequency mode. A second TCQ can comprise a third frequency mode and a fourth frequency mode. First TCQ can be selectively coupled to a first qubit based on the first frequency mode and selectively coupled to the second TCQ based on the second and third frequency modes. Second TCQ can be selectively coupled to a second qubit based on the fourth frequency mode. When certain respective magnetic fluxes are applied to first and second TCQs, ZZ interaction between the first and second qubits can be suppressed. When respective modified magnetic fluxes are applied to first and second TCQs to excite respective frequency modes, coupling can occur, and ZZ interaction and an entangled gate can be created between the first and second qubits.

Abstract: A package structure comprises a first quantum bit chip and a second quantum bit chip bonded to an interposer, and a differential coupling bus. The differential coupling bus is configured to differentially couple the first quantum bit chip and the second quantum bit chip at least in part through differential transmission lines disposed on the interposer.

Abstract: Devices and/or computer-implemented methods to facilitate a multipole filter on a quantum device with multiplexing capability and signal separation to mitigate crosstalk are provided. According to an embodiment, a device can comprise an interposer substrate comprising a readout resonator. The device can further comprise a qubit chip substrate comprising a qubit coupled to the readout resonator and to a multipole filter.

Abstract: One or more systems, devices and/or computer-implemented methods of use provided herein relate to single-device readout of the state of a coupler qubit and flux control of that coupler qubit, which processes can be performed simultaneously. In one or more embodiments, an electronic system comprises a coupler qubit, a pair of superconducting qubits coupled to the coupler qubit, a multiplexed input line, and a readout and flux control subsystem coupled between the multiplexed input line and the coupler qubit, wherein the readout and flux control subsystem is configured to allow for both readout of a state of the coupler qubit and flux control that adjusts a coupling between the pair of superconducting qubits. The diplexer couples together the readout resonator and a flux control portion of the electronic system, wherein the readout resonator and the flux control portion are separated from one another between the diplexer and the coupler qubit.

Abstract: Devices and/or computer-implemented methods to facilitate ZZ cancellation between qubits are provided. According to an embodiment, a device can comprise a coupler device that operates in a first oscillating mode and a second oscillating mode. The device can further comprise a first superconducting qubit coupled to the coupler device based on a first oscillating mode structure corresponding to the first oscillating mode and based on a second oscillating mode structure corresponding to the second oscillating mode. The device can further comprise a second superconducting qubit coupled to the coupler device based on the first oscillating mode structure and the second oscillating mode structure.

Abstract: Systems and techniques that facilitate mode-selective couplers for frequency collision reduction are provided. In various embodiments, a device can comprise a control qubit. In various aspects, the device can comprise a first target qubit coupled to the control qubit by a first mode-selective coupler. In various instances, the first mode-selective coupler can facilitate A-mode coupling between the control qubit and the first target qubit. In various embodiments, the device can comprise a second target qubit coupled to the control qubit by a second mode-selective coupler. In various aspects, the second mode selective coupler can facilitate B-mode coupling between the control qubit and the second target qubit. In various embodiments, the first mode-selective coupler can comprise a capacitor that capacitively couples a middle capacitor pad of the control qubit to a middle capacitor pad of the first target qubit.

Abstract: Devices and/or computer-implemented methods facilitating static ZZ suppression and Purcell loss reduction using mode-selective coupling in two-junction superconducting qubits are provided. In an embodiment, a device can comprise a superconducting bus resonator. The device can further comprise a first superconducting qubit. The device can further comprise a second superconducting qubit, the first superconducting qubit and the second superconducting qubit respectively comprising: a first superconducting pad; a second superconducting pad; a third superconducting pad; a first Josephson Junction coupled to the first superconducting pad and the second superconducting pad; and a second Josephson Junction coupled to the second superconducting pad and the third superconducting pad. The first superconducting pad and the second superconducting pad of the first superconducting qubit and the second superconducting qubit are coupled to the superconducting bus resonator.

Abstract: Devices and/or computer-implemented methods to facilitate ZZ cancellation between qubits are provided. According to an embodiment, a device can comprise a coupler device that operates in a first oscillating mode and a second oscillating mode. The device can further comprise a first superconducting qubit coupled to the coupler device based on a first oscillating mode structure corresponding to the first oscillating mode and based on a second oscillating mode structure corresponding to the second oscillating mode. The device can further comprise a second superconducting qubit coupled to the coupler device based on the first oscillating mode structure and the second oscillating mode structure.

Abstract: Devices and/or computer-implemented methods facilitating static ZZ suppression and Purcell loss reduction using mode-selective coupling in two junction superconducting qubits are provided. In an embodiment, a device can comprise a superconducting bus resonator. The device can further comprise a first superconducting qubit. The device can further comprise a second superconducting qubit, the first superconducting qubit and the second superconducting qubit respectively comprising: a first superconducting pad; a second superconducting pad; a third superconducting pad; a first Josephson Junction coupled to the first superconducting pad and the second superconducting pad; and a second Josephson Junction coupled to the second superconducting pad and the third superconducting pad. The first superconducting pad and the second superconducting pad of the first superconducting qubit and the second superconducting qubit are coupled to the superconducting bus resonator.

Abstract: One or more systems, devices, or methods of use provided herein relate to a process of long-range coupling qubits in a quantum computing device with energy loss protection. A system can comprise a first transmon coupler capable of selectively coupling a first tunable coupler qubit to a first fluxonium qubit; a second transmon coupler capable of selectively coupling a second tunable coupler qubit to a second fluxonium qubit. Additionally, in one or more embodiments, the system can include a long-range coupler capable of selectively coupling the first fluxonium qubit to the second fluxonium qubit. The first transmon coupler can be coupled to a first B mode of the first tunable coupler qubit, and the second transmon coupler can be coupled to a second B mode of the second tunable coupler qubit.

Abstract: Devices and/or computer-implemented methods to facilitate ZZ cancellation between qubits are provided. According to an embodiment, a device can comprise a coupler device that operates in a first oscillating mode and a second oscillating mode. The device can further comprise a first superconducting qubit coupled to the coupler device based on a first oscillating mode structure corresponding to the first oscillating mode and based on a second oscillating mode structure corresponding to the second oscillating mode. The device can further comprise a second superconducting qubit coupled to the coupler device based on the first oscillating mode structure and the second oscillating mode structure.

Abstract: Techniques and couplers for managing coupling between qubits are presented. A first tuneable coupler qubit (TCQ) can comprise a first frequency mode and a second frequency mode. A second TCQ can comprise a third frequency mode and a fourth frequency mode. First TCQ can be selectively coupled to a first qubit based on the first frequency mode and selectively coupled to the second TCQ based on the second and third frequency modes. Second TCQ can be selectively coupled to a second qubit based on the fourth frequency mode. When certain respective magnetic fluxes are applied to first and second TCQs, ZZ interaction between the first and second qubits can be suppressed. When respective modified magnetic fluxes are applied to first and second TCQs to excite respective frequency modes, coupling can occur, and ZZ interaction and an entangled gate can be created between the first and second qubits.

Abstract: A device comprises a data quantum bit, a first quantum bit coupler, a second quantum bit coupler, and an auxiliary quantum bit. The first quantum bit coupler is coupled to the data quantum bit. The second quantum bit coupler is coupled to the first quantum bit coupler. The auxiliary quantum bit is coupled to the second quantum bit coupler. The first quantum bit coupler is configured to operate in a state to suppress interaction between the data quantum bit and the auxiliary quantum bit. The first quantum bit coupler and the second quantum bit coupler are each configured to operate in a respective state to enable interaction between the data quantum bit and the auxiliary quantum bit and entangle a state of the data quantum bit with a state of the auxiliary quantum bit.

Abstract: A device comprises first and second superconducting quantum bits, and a multimode coupler circuit coupled between the first and second superconducting quantum bits. The multimode coupler circuit comprises a first mode and a second mode, and is configured to operate in one of a first state and a second state, in response to a flux tuning control signal. In the first state, the first superconducting quantum bit is exchange coupled to the first mode, and the second superconducting quantum bit is exchange coupled to the second mode, to suppress interaction between the first and second superconducting quantum bits. In the second state, the first and second superconducting quantum bits are exchange coupled to both the first and second modes, to enable an interaction between the first and second superconducting quantum bits and perform an entanglement gate operation.

Abstract: A device comprises a first superconducting quantum bit, a second superconducting quantum bit, and a coupler circuit. The first superconducting quantum bit comprises a superconducting tunnel junction and a shunt inductor which form a first superconducting loop. The second superconducting quantum bit comprises a superconducting tunnel junction and a shunt inductor which form a second superconducting loop. The coupler circuit is coupled between the first and second superconducting quantum bits. The coupler circuit is configured to implement an entanglement gate operation between the first and second superconducting quantum bits through exchange interactions between the coupler circuit and the first superconducting quantum bit and the second superconducting quantum bit, when the coupler circuit is driven by a control signal.

Abstract: An apparatus comprising a first qubit has a first driving frequency and a second qubit electrically connected to the first qubit, wherein the second qubit has a second driving frequency, wherein the second driving frequency is different than the first driving frequency. A readout resonator electrically connected to the first qubit and the second qubit and a filter electrically connected to the readout resonator, wherein the filter allows for the first qubit to be driven at the second driving frequency of the second qubit. A drive unit electrically connected to the filter.

Abstract: Devices and/or computer-implemented methods facilitating static ZZ suppression and Purcell loss reduction using mode-selective coupling in two junction superconducting qubits are provided. In an embodiment, a device can comprise a superconducting bus resonator. The device can further comprise a first superconducting qubit. The device can further comprise a second superconducting qubit, the first superconducting qubit and the second superconducting qubit respectively comprising: a first superconducting pad; a second superconducting pad; a third superconducting pad; a first Josephson Junction coupled to the first superconducting pad and the second superconducting pad; and a second Josephson Junction coupled to the second superconducting pad and the third superconducting pad. The first superconducting pad and the second superconducting pad of the first superconducting qubit and the second superconducting qubit are coupled to the superconducting bus resonator.