D-wave Systems Inc.

1372934 B.c. Ltd

Loren J Swenson

Mark H Volkmann

Jed D Whittaker

George E G Sterling

Andrew Joseph Berkley

Trevor Michael Lanting

Andrew Douglas King

Emile M Hoskinson

Colin C Enderud

Steven Paul Reinhardt

Warren T E Wilkinson

Paul I Bunyk

Richard G Harris

Eric G Ladizinsky

Byong Hyop Oh

Christopher B Rich

Peter D Spear

Douglas P Stadtler

Ilya V Perminov

Jason J Yao

Shuiyuan Huang

Fabio Altomare

Nicolas C Ladizinsky

Abraham J Evert

Edward G Sterpka

Catia Baron Aznar

Michael S Babcock

Superconducting integrated circuits and methods of forming these circuits are discussed. One superconducting integrated circuit has a substrate and a control device formed by a layer of high kinetic inductance material overlying the substrate. The control device has a loop of material, electrical connections between the loop of material and a power line, a coupling element connected to the loop of material, a pair of Josephson junctions that interrupt the loop of material, and an energy storage element connected to the loop of material. An alternative superconducting integrated circuit has a kinetic inductance device formed in a high kinetic inductance layer. The device has a compound Josephson junction structure with two parallel current paths with respective Josephson junctions, a loop of material connected to the compound Josephson junction structure, and a coupling structure. The circuit also has an additional device that couples to the coupling structure.

Kinetic inductance devices, methods for fabricating kinetic inductance devices, and articles employing the same

A filter multiplexer for variable bandwidth annealing selection is described. The filter multiplexer has multiple pathways, where each pathway comprises a switch and a filter. Each filter has a different cutoff frequency from the other filters. Switches may be cryogenic switches. Each pathway may be communicatively coupled to an external annealing line. Upon receiving a problem, an annealing bandwidth can be selected, set or configured via the multiplexer to operate a quantum processor with a desired annealing schedule. The multiplexer may be used for calibration of a quantum processor by performing a calibration with a large annealing bandwidth, then calibrating the quantum processor by iterating through all available annealing bandwidths from the multiplexer.

Systems and methods for variable bandwidth annealing

Computational systems and methods employ characteristics of a quantum processor determined or sampled between a start and an end of an annealing evolution per an annealing schedule. The annealing evolution can be reinitialized, reversed or continued after determination. The annealing evolution can be interrupted. The annealing evolution can be ramped immediately prior to or as part of determining the characteristics. The annealing evolution can be paused or not paused immediately prior to ramping. A second representation of a problem can be generated based at least in part on the determined characteristics from an annealing evolution performed on a first representation of the problem. The determined characteristics can be autonomously compared to an expected behavior, and alerts optionally provided and/or the annealing evolution optionally terminated based on the comparison. Iterations of annealing evolutions may be performed until an exit condition occurs.

Quantum annealing debugging systems and methods

Superconducting integrated circuits may advantageously employ superconducting resonators coupled to a microwave transmission line to efficiently address superconducting flux storage devices. In an XY-addressing scheme, a global flux bias may be applied to a number of superconducting flux storage devices via a low-frequency address line, and individual superconducting flux storage devices addressed via application of high-frequency pulses via resonators driven by the microwave transmission line. Frequency multiplexing can be employed to provide signals to two or more resonators. A low-frequency current bias may be combined with a high-frequency current in one or more superconducting resonators to provide Z-addressing. A low-frequency current bias may be combined with a high-frequency current in one or more superconducting resonators to eliminate a flux bias line. A low-frequency current bias may be used at room temperature to identify the presence of a DC short, an open, and/or an unexpected resistance in a superconducting resonator.

Systems and methods for addressing devices in a superconducting circuit

A superconducting circuit may include a transmission line having at least one transmission line inductance, a superconducting resonator, and a coupling capacitance that communicatively couples the superconducting resonator to the transmission line. The transmission line inductance may have a value selected to at least partially compensate for a variation in a characteristic impedance of the transmission line, the variation caused at least in part by the coupling capacitance. The coupling capacitance may be distributed along the length of the transmission line. A superconducting circuit may include a transmission line having at least one transmission line capacitance, a superconducting resonator, and a coupling inductance that communicatively couples the superconducting resonator to the transmission line. The transmission line capacitance may be selected to at least partially compensate for a variation in coupling strength between the superconducting resonator and the transmission line.

Systems and methods for coupling a superconducting transmission line to an array of resonators

A circuit can include a galvanic coupling of a coupler to a qubit by a segment of kinetic inductance material. The circuit can include a galvanic kinetic inductance coupler having multiple windings. The circuit can include a partially-galvanic coupler having multiple windings. The partially-galvanic coupler can include a magnetic coupling and a galvanic coupling. The circuit can include an asymmetric partially-galvanic coupler having a galvanic coupling and a first magnetic coupling to one qubit and a second magnetic coupling to a second qubit. The circuit can include a compact kinetic inductance qubit having a qubit body loop comprising a kinetic inductance material. A multilayer integrated circuit including a kinetic inductance layer can form a galvanic kinetic inductance coupling. A multilayer integrated circuit including a kinetic inductance layer can form at least a portion of a compact kinetic inductance qubit body loop.

Kinetic inductance for couplers and compact qubits

Various techniques and apparatus permit fabrication of superconductive circuits. A superconducting integrated circuit comprising a superconducting stud via, a kinetic inductor, and a capacitor may be formed. Forming a superconducting stud via in a superconducting integrated circuit may include masking with a hard mask and masking with a soft mask. Forming a superconducting stud via in a superconducting integrated circuit may include depositing a dielectric etch stop layer. Interlayer misalignment in the fabrication of a superconducting integrated circuit may be measured by an electrical vernier. Interlayer misalignment in the fabrication of a superconducting integrated circuit may be measured by a chain of electrical verniers and a Wheatstone bridge. A superconducting integrated circuit with three or more metal layers may include an enclosed, matched, on-chip transmission line. A metal wiring layer in a superconducting integrated circuit may be encapsulated.

Systems and methods for fabrication of superconducting integrated circuits

A device is dynamically isolated via a broadband switch that includes a plurality of cascade elements in series, wherein each cascade element comprises a first set of SQUIDs in series, a matching capacitor, and a second set of SQUIDs in series. The broadband switch is set to a passing state via flux bias lines during programming and readout of the device and set to a suppression state during device's calculation to reduce operation errors at the device. A device is electrically isolated from high-frequencies via an unbiased broadband switch. A device is coupled to a tunable thermal bath that includes a broadband switch.

Dynamical isolation of a cryogenic processor

A superconducting readout system employing a microwave transmission line, and a microwave superconducting resonator communicatively coupled to the microwave transmission line, and including a superconducting quantum interference device (SQUID), may be advantageously calibrated at least in part by measuring a resonant frequency of the microwave superconducting resonator in response to a flux bias applied to the SQUID, measuring a sensitivity of the resonant frequency in response to the flux bias, and selecting an operating frequency and a sensitivity of the microwave superconducting resonator based at least in part on a variation of the resonant frequency as a function of the flux bias. The flux bias may be applied to the SQUID by an interface inductively coupled to the SQUID. Calibration of the superconducting readout system may also include determining at least one of a propagation delay, a microwave transmission line delay, and a microwave transmission line phase offset.

Systems and methods for operation of a frequency multiplexed resonator input and/or output for a superconducting device

Addressing a superconducting flux storage device may include applying a bias current, a low-frequency flux bias, and a high-frequency flux bias in combination to cause a combined address signal level to exceed a defined address signal latching level for the superconducting flux storage device. A bias current that, in combination with a low-frequency flux bias and a high-frequency flux bias, causes a combined address signal level to exceed a defined address signal latching level for a superconducting flux storage device is at least reduced by an asymmetry in the Josephson junctions of the CJJ. A low-frequency flux bias that, in combination with a bias current and a high-frequency flux bias, causes a combined address signal level to exceed a defined address signal latching level for a superconducting flux storage device is at least reduced by an asymmetry in the Josephson junctions of the CJJ.

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Loren J Swenson