Abstract: A device comprises a superconducting square pulse waveform generator which comprises a self-oscillating circuit that is configured to generate a continuous sequence of square current pulses in response to a single flux quantum (SFQ) pulse applied to an input port of the superconducting square pulse waveform generator. The self-oscillating circuit is responsive to a first direct current (DC) control signal to tune a pulse period of the continuous sequence of square current pulses, and responsive to a second DC control signal to tune a pulse width of the square current pulses.

Abstract: A device comprises a superconducting switch which comprises an impedance tunable element coupled to and between a transmission line and ground. The transmission line couples a first port and a second port having matched impedances. The impedance tunable element comprises a superconducting loop comprising at least one Josephson junction, and is configured to be flux tuned into a first or second impedance state. In the first impedance state, the impedance tunable element shunts the transmission line to ground with an impedance that disrupts the impedance match between the first and second ports to suppress signal transmission between the first and second ports over the transmission line. In the second impedance state, the impedance tunable element shunts the transmission line to ground with an impedance that maintains the impedance match between the first and second ports to allow signal transmission between the first and second ports over the transmission line.

Abstract: A device comprises a superconducting radio frequency (RF) signal generator which comprises a plurality of channels. Each channel is configured to generate a corresponding RF signal with a frequency that is controlled by a corresponding direct current (DC) control signal applied to the channel.

Abstract: A device includes a first set of circuit components implementing a qubit and a second set of circuit components implementing a readout resonator for reading out a state of the qubit. A first footprint of the first set of circuit components overlaps a second footprint of the second set of circuit components. The first footprint is oriented relative to the second footprint based on a first electric dipole of the first set of circuit components and a second electric dipole of the second set of circuit components.

Abstract: A method is provided for fabricating a multilevel wiring structure. A first metallization layer comprising a superconducting metal is formed in a surface of a first substrate. A second substrate is bonded to the first substrate. The second substrate comprises a monocrystalline dielectric material. The second substrate is thinned to form an interlayer dielectric layer which comprises the monocrystalline dielectric material. A second metallization layer comprising a superconducting metal is formed in a surface of the interlayer dielectric layer. The second metallization layer is connected to the first metallization layer by at least one interlayer via in the interlayer dielectric layer.

Abstract: A device includes a first set of circuit components implementing a qubit and a second set of circuit components implementing a readout resonator for reading out a state of the qubit. A first footprint of the first set of circuit components overlaps a second footprint of the second set of circuit components. The first footprint is oriented relative to the second footprint based on a first electric dipole of the first set of circuit components and a second electric dipole of the second set of circuit components.

Abstract: A device comprises a superconducting radio frequency (RF) signal generator which comprises a plurality of channels. Each channel is configured to generate a corresponding RF signal with a frequency that is controlled by a corresponding direct current (DC) control signal applied to the channel.

Abstract: A quantum structure includes a flux bias coil having a first inductive element and a second inductive element. A magnetic induction of the first inductive element is opposite to a magnetic induction of the second inductive element. A superconducting quantum interference device (SQUID) is within a footprint of the first inductive element. A first flux bias line is coupled to the first inductive element and a second flux bias line is coupled to the second inductive element. A routing of the first and second flux bias lines is on one or more planes separate from the flux bias coil.

Abstract: A device comprises a superconducting quantum circuit comprising a coupler which is coupled to a first quantum bit and a second quantum bit. The coupler comprises a tunable coupler and a fixed coupler. The coupler is configured to operate in a first mode to suppress coupling between the first quantum bit and the second quantum bit, when the tunable coupler is tuned to have a first frequency which corresponds to a fixed frequency of the fixed coupler. The coupler is configured to operate in a second mode to enable coupling between the first quantum bit and the second quantum bit, when the tunable coupler is tuned to have a second frequency which is different from the fixed frequency of the fixed coupler.

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: A package structure comprises a first quantum bit chip and a second quantum bit chip mounted on a carrier substrate. The carrier substrate comprises an inter-chip coupling network which is configured to provide non-galvanic and differential coupling of the first quantum bit chip and the second quantum bit chip.

Abstract: A device includes a first set of circuit components implementing a qubit and a second set of circuit components implementing a readout resonator for reading out a state of the qubit. A first footprint of the first set of circuit components overlaps a second footprint of the second set of circuit components. The first footprint is oriented relative to the second footprint based on a first electric dipole of the first set of circuit components and a second electric dipole of the second set of circuit components.

Abstract: Techniques facilitating a quantum gate between qubits using a tunable coupler are provided. In one example, a quantum coupler device can comprise a Josephson ring modulator (JRM) that is operatively coupled to first and second qubits in a balanced bridge topology via respective first and second capacitive devices. The JRM provides tunable coupling between the first and second qubits.

Abstract: A qubit system includes a qubit located on a first substrate. A readout resonator is coupled to the qubit and located on substrate having an attenuation constant the same as the first substrate. A first Purcell filter coupled to the readout resonator and located on a second substrate. The first substrate comprises a material that has an attenuation constant that is lower than that of the second substrate.

Abstract: A quantum semiconductor device includes a qubit chip; an interposer chip, with a handler, including a through-silicon-via (TSV) coupled to a first side of the qubit chip. A multi-level wiring (MLW) layer contacts an underside of the interposer chip and coupling to the top side of the handler, the TSV facilitates an electrical signal connection between the MLW layer, a topside of the interposer chip and the qubit chip, wherein structure of the device mitigates signal cross-talk across respective lines of the MLW layer.

Abstract: Techniques facilitating a quantum gate between qubits using a tunable coupler are provided. In one example, a quantum coupler device can comprise a Josephson ring modulator (JRM) that is operatively coupled to first and second qubits in a balanced bridge topology via respective first and second capacitive devices. The JRM provides tunable coupling between the first and second qubits.

Abstract: A system and method for characterizing incident ions are provided. The method includes positioning a transmission line detector to receive incident ions, the transmission line detector comprising a superconducting meandering wire defining a detection area for incident ions, and applying a bias current to the transmission line detector. The method also includes detecting a first signal produced in the transmission line detector due to an ion impacting the detection area, and detecting a second signal produced in the transmission line detector due to the ion impacting the detection area. The method further includes analyzing the first signal and the second signal to characterize the ion. In some aspects, the method further includes identifying a delay between the first signal and the second signal to determine, using the identified delay, a location of the ion on the detection area.

Abstract: A system and method for characterizing incident ions are provided. The method includes positioning a transmission line detector to receive incident ions, the transmission line detector comprising a superconducting meandering wire defining a detection area for incident ions, and applying a bias current to the transmission line detector. The method also includes detecting a first signal produced in the transmission line detector due to an ion impacting the detection area, and detecting a second signal produced in the transmission line detector due to the ion impacting the detection area. The method further includes analyzing the first signal and the second signal to characterize the ion. In some aspects, the method further includes identifying a delay between the first signal and the second signal to determine, using the identified delay, a location of the ion on the detection area.