International Business Machines Corporation

David C Mckay

Jay Michael Gambetta

Abhinav Kandala

Ali Javadiabhari

Jerry M Chow

Patryk Gumann

Sarah Elizabeth Sheldon

Easwar Magesan

Oliver Dial

Srikanth Srinivasan

Isaac Lauer

David Louis Kaminsky

Russell Alan Budd

Elbert Emin Huang

Mark N Wegman

John A Gunnels

Martin O Sandberg

Vivekananda P Adiga

Charles Thomas Rettner

Jared Barney Hertzberg

Hanhee Paik

Jeffrey Joseph Ruedinger

Andrew W Cross

Sergey Bravyi

Antonio Corcoles-Gonzalez

Maika Takita

Thomas Arab Alexander

Prakash Murali

Michael Justin Beckley

Devendra K Sadana

Stephen W Bedell

Steven J Holmes

Ning Li

Jason Scott Orcutt

Salvatore Bernardo Olivadese

Sean Hart

Matthias Steffen

George Andrew Keefe

Francisco Jose Martin Fernandez

Muir Kumph

Xuan Wei

Valerio A Grendanin

Christopher W Surovic

Moein Malekakhlagh

David Zarsky

Gilbert Bauer

Raymond A Watters

Ismael Faro Serfage

Robert Meinel

Devices and/or computer-implemented methods to facilitate a programmable and/or reprogrammable quantum circuit are provided. According to an embodiment, a device can comprise a superconducting coupler device having a superconducting fuse device that is used to alter the coupling of a first quantum computing element and a second quantum computing element.

Programmable and reprogrammable quantum circuit

Techniques facilitating custom thermal shields for cryogenic environments are provided. In one example, a cryostat can comprise a thermal shield extending between a thermal stage and a base structure coupled to a bottom plate of an outer vacuum chamber. The thermal stage can be coupled to a top plate of the outer vacuum chamber. The thermal shield can provide access to a sample mounting surface encompassed within the thermal shield from a region external to the outer vacuum chamber via the top and bottom plates of the outer vacuum chamber.

Custom thermal shields for cryogenic environments

Systems, computer-implemented methods, and computer program products to facilitate mapping conditional execution logic to different quantum computing resources 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 a compiler component that maps a logical reference to a quantum bit data structure in an instruction, to a first engine component, and a deployment component that deploys the first engine component to a first block controller component operatively connected to a first quantum computing resource, wherein the first engine component controls the first quantum computing resource based on the instruction.

Mapping conditional execution logic to quantum computing resources

Systems and techniques that facilitate Stark shift cancellation are provided. In various embodiments, a system can comprise a control qubit that is coupled to a target qubit. In various cases, the control qubit can be driven by a first tone that entangles the control qubit with the target qubit. In various aspects, the control qubit can be further driven by a second tone simultaneously with the first tone. In various cases, the second tone can have an opposite detuning sign than the first tone. In various instances, the first tone can cause a Stark shift in an operational frequency of the control qubit, and the second tone can cancel the Stark shift.

Stark shift cancellation

Systems and techniques that facilitate space-saving coupler arm arrangement for superconducting qubits are provided. In various embodiments, a device can comprise a superconducting qubit. In various aspects, the superconducting qubit can be capacitively coupled to two or more coupler arms. In various instances, a parasitic capacitance between the two or more coupler arms can be within an order of magnitude of a capacitance between the superconducting qubit and at least one of the two or more coupler arms. In various cases, the parasitic capacitance can arise due to a physical proximity between the two or more coupler arms.

Space-saving coupler arm arrangement for superconducting qubits

Systems, computer-implemented methods, and computer program products to facilitate quantum state measurement logic used in a quantum state measurement backend process 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 a stage control register component that defines a data processing function corresponding to at least one storage element in at least one stage of a quantum state measurement pipeline.

Quantum state measurement logic facilitating a quantum state measurement backend process

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

Techniques regarding qubit coupling structures that enable RIP gates are provided. For example, one or more embodiments described herein can comprise an apparatus that can include a coupling structure coupled to a first qubit and a second qubit. The coupling structure can have a plurality of coupling pathways. A coupling pathway from the plurality of coupling pathways can be a resonator. Also, the first qubit can be coupled to a first end of the resonator, and the second qubit can be coupled to a point along a length of the resonator.

Multimode resonators for resonator induced phase gates

A method of mitigating quantum readout errors by stochastic matrix inversion includes performing a plurality of quantum measurements on a plurality of qubits having predetermined plurality of states to obtain a plurality of measurement outputs; selecting a model for a matrix linking the predetermined plurality of states to the plurality of measurement outputs, the model having a plurality of model parameters, wherein a number of the plurality of model parameters grows less than exponentially with a number of the plurality of qubits; training the model parameters to minimize a loss function that compares predictions of the model with the matrix; computing an inverse of the model based on the trained model parameters; and providing the computed inverse of the model to a noise prone quantum readout of the plurality of qubits to obtain a substantially noise free quantum readout.

Quantum readout error mitigation by stochastic matrix inversion

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

Systems, computer-implemented methods, and computer program products to facilitate characterizing crosstalk of a quantum computing system based on sparse data collection 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 a package component that packs subsets of quantum gates in a quantum device into one or more bins. The computer executable components can further comprise an assessment component that characterizes crosstalk of the quantum device based on a number of the one or more bins into which the subsets of quantum gates are packed.

Characterizing crosstalk of a quantum computing system based on sparse data collection

Systems and techniques that facilitate multi-resonant couplers for preserving ZX interaction while reducing ZZ interaction are provided. In various embodiments, a first qubit can have a first operational frequency and a second qubit can have a second operational frequency, and a multi-resonant architecture can couple the first qubit to the second qubit. In various embodiments, the multi-resonant architecture can comprise a first resonator and a second resonator. In various cases, the first resonator can capacitively couple the first qubit to the second qubit, and a second resonator can capacitively couple the first qubit to the second qubit. In various aspects, the first resonator and the second resonator can be in parallel. In various instances, the first resonator can have a first resonant frequency less than the first operational frequency and the second operational frequency, and the second resonator can have a second resonant frequency greater than the first operational frequency and the second operational frequency. In various other embodiments, the multi-resonant architecture can comprise a resonator, a first end of which can be capacitively coupled to the first qubit and to the second qubit, and a second end of which can be coupled to ground. In various instances, the resonator can have a first harmonic less than the first operational frequency and the second operational frequency, and can have a second harmonic greater than the first operational frequency and the second operational frequency. In various other embodiments, the multi-resonant architecture can comprise a resonator and a direct coupler. In various embodiments, the resonator and the direct coupler can both capacitively couple the first qubit to the second qubit, and the resonator and the direct coupler can be in parallel. In various cases, the direct coupler can couple opposite pads of the first qubit and the second qubit. In various embodiments, a first end of the resonator can be capacitively coupled to the first qubit and the second qubit, a second end of the resonator can be coupled to ground, and the direct coupler can capacitively couple common pads of the first qubit and the second qubit.

Multi-resonant coupling architectures for ZZ interaction reduction

A quantum computing device including a first plurality of qubits having a first resonance frequency and a second qubit having a second resonance frequency, the second resonance frequency being different from the first resonance frequency; and a first tunable frequency bus configured to couple the first plurality of qubits to the second qubit.

Quantum computing device using two gate types to prevent frequency collisions in superconducting quantum computers

Systems and techniques that facilitate quantum tuning via permanent magnetic flux elements are provided. In various embodiments, a system can comprise a qubit device. In various aspects, the system can further comprise a permanent magnet having a first magnetic flux, wherein an operational frequency of the qubit device is based on the first magnetic flux. In various instances, the system can further comprise an electromagnet having a second magnetic flux that tunes the first magnetic flux. In various cases, the permanent magnet can comprise a nanoparticle magnet. In various embodiments, the nanoparticle magnet can comprise manganese nanoparticles embedded in a silicon matrix. In various aspects, the system can further comprise an electrode that applies an electric current to the nanoparticle magnet in a presence of the second magnetic flux, thereby changing a strength of the first magnetic flux.

Quantum tuning via permanent magnetic flux elements

Growing community of inventors

Ossining, NY, United States of America

David C Mckay