International Business Machines Corporation

Antonio Corcoles-Gonzalez

Jay Michael Gambetta

Maika Takita

Sami Rosenblatt

Markus Brink

Firat Solgun

Jerry M Chow

Lev Samuel Bishop

Paul Kristan Temme

Scott Douglas Lekuch

Ken Inoue

Salvatore Bernardo Olivadese

David C Mckay

Jason Scott Orcutt

Patryk Gumann

Jared Barney Hertzberg

Youngseok Kim

Andrew W Cross

Easwar Magesan

Oliver Dial

John Aaron Smolin

Theodore James Yoder

Neereja Sundaresan

Moein Malekakhlagh

Jinsung Kim

Edward Hong Chen

Systems, computer-implemented methods, and computer program products that can facilitate determining a state of a qubit are described. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise an output receiving component that can receive, in response to a request, output representative of a quantum state of a qubit of a quantum computing device, and a classifying component that classifies the quantum state of the qubit of the quantum computing device based on the output representative of the quantum state of the qubit. The system can further include a configuring component that can configure the classifying component based on a characteristic of the request.

Phase-robust matched kernel acquisition for qubit state determination

One or more systems, devices, computer program products and/or computer-implemented methods of use provided herein relate to a process to dynamically determine a threshold for determining a state of a qubit and apply the threshold for operating a pulse to de-excite the qubit. A system can comprise a memory that stores computer executable components, and a processor that executes the computer executable components stored in the memory, wherein the computer executable components can comprise a decision component that is configured to determine a threshold of a plurality of thresholds to apply to measurement of a state of a qubit based on a probability distribution of state of the qubit, wherein a measurement at one side of the threshold is representative of the qubit being in the ground state, and wherein a measurement at another side of the threshold is representative of the qubit being in an excited state.

Dynamic adaptive thresholding for qubit reset

Techniques regarding tiling a CR gate configuration to one or more lattices characterizing quantum circuit topologies are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a tiling component that can generate a cross-resonance gate configuration that delineates a control qubit assignment and a target qubit assignment in conjunction with a frequency allocation onto a lattice characterizing a quantum circuit topology.

Tiling of cross-resonance gates for quantum circuits

Systems and techniques that facilitate strategic pausing for quantum state leakage mitigation are provided. In various embodiments, a system can comprise a detection component that can detect a quantum state leakage associated with one or more qubits. In various aspects, the system can further comprise a pause component that can, in response to detecting the quantum state leakage, generate a time pause prior to execution of a quantum circuit on the one or more qubits. In various embodiments, the pause component can generate the time pause after execution of a previous quantum circuit on the one or more qubits, where the quantum state leakage arises during the execution of the previous quantum circuit. In some cases, the quantum state leakage can decay during the time pause.

Strategic pausing for quantum state leakage mitigation

Techniques regarding calibrating one or more quantum decoder algorithms are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a correlation inversion decoder component that can calibrate a quantum decoder algorithm for decoding a quantum error-correcting code by estimating hyperedge probabilities of a decoding hypergraph that are consistent with a syndrome dataset.

Calibrated decoders for implementations of quantum codes

Techniques facilitating multiple cryogenic systems sectioned within a common vacuum space are provided. In one example, a cryostat can comprise a plurality of thermal stages and a thermal switch. The plurality of thermal stages can intervene between a 4-Kelvin (K) stage and a Cold Plate stage. The plurality of thermal stages can include a Still stage and an intermediate thermal stage that can be directly coupled mechanically to the Still stage via a support rod. The thermal switch can be coupled to the intermediate thermal stage and an adjacent thermal stage. The thermal switch can facilitate modifying a thermal profile of the cryostat by providing a switchable thermal path between the intermediate thermal stage and the adjacent thermal stage.

Multiple cryogenic systems sectioned within a common vacuum space

A method for characterizing noise in a quantum system, the quantum system including a plurality of qubits and a plurality of entangling gates native to the quantum system, includes generating a random quantum circuit on a quantum processor, the random quantum circuit comprising the plurality of entangling gates native to the quantum system. The method includes running a simulation of the random quantum circuit on a classical computer a plurality of times to obtain ideal outcomes, and running the random quantum circuit on the quantum processor a plurality of times to obtain experimental outcomes. The method includes grouping the experimental outcomes based on probabilities of the ideal outcomes to obtain a first distribution, and grouping the experimental outcomes based on probabilities of the experimental outcomes to obtain a second distribution. The method includes characterizing noise in the quantum system based on the first distribution and the second distribution.

Noise classification through the output of random quantum circuits

A signal generating system is provided. The signal generating system provides a microwave signal to a plurality of qubits. The signal generating system includes a generator, an oscillator, a mixer, and a splitter. The oscillator generates an oscillator signal including a constant frequency. The generator generates a generator signal including an initial frequency. The mixer is electrically coupled to the generator and the oscillator. The mixer combines the generator and oscillator signals to produce the microwave signal. The splitter is electrically coupled to the mixer. The splitter fans-out the microwave signal to a plurality of physical lines. Each of the plurality of physical lines is electrically connected to a corresponding one of the plurality of qubits.

Cross-resonance fan-out for efficiency and hardware reduction

Techniques and a system to facilitate quantum computation are provided. In one example, a system includes a processor that executes computer executable components stored in a memory; a quantum feature map circuit component that estimates a kernel associated with a feature map; and a support vector machine component that performs a classification using the estimated kernel.

Quantum feature kernel estimation using an alternating two layer quantum circuit

Systems, computer-implemented methods, and computer program products to facilitate external port measurement of qubit port responses are provided. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise an analysis component that can analyze responses of a multi-mode readout device coupled to a qubit. The computer executable components can further comprise an assignment component that can assign a readout state of the qubit based on the responses. In some embodiments, the multi-mode readout device can be electrically coupled to at least one of the qubit or an environment of the qubit based on a defined electrical coupling value.

Multi-mode qubit readout and qubit state assignment

A technique relates a structure. An inductive element is on a first surface. A capacitive element is on the first surface and a second surface. An interconnect structure is between the first surface and the second surface.

Bumped resonator structure

A technique relates to a structure. A first surface includes an inductive element of a resonator. A second surface includes a first portion of a capacitive element of the resonator and at least one qubit. A second portion of the capacitive element of the resonator is on the first surface.

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Mount Kisco, NY, United States of America

Antonio Corcoles-Gonzalez