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公开(公告)号：US20220067567A1
公开(公告)日：2022-03-03
申请号：US17464278
申请日：2021-09-01
Applicant: Google LLC
Inventor： Thomas Eugene O`Brien , Ryan Babbush , Nicholas Charles Rubin , Jarrod Ryan McClean
Abstract: Methods, systems, and apparatus for verified quantum phase estimation. In one aspect, a method includes repeatedly performing a experiment. Performing one repetition of the experiment includes: applying a second unitary to a system register of N qubits prepared in a target computational basis state; applying, conditioned on a state of a control qubit, a first unitary to the system register; applying an inverse of the second unitary to the system register and measuring each qubit to determine an output state of the system register; measuring the control qubit to obtain a corresponding measurement result m; and post-selecting on the target computational basis state by, in response to determining that the output state indicates that each qubit was in the target computational basis state prior to measurement, incrementing a first or second classical variable by (−1)m. Phases or expectation values of the first unitary are estimated based on the classical variables.
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公开(公告)号：US11244240B2
公开(公告)日：2022-02-08
申请号：US16301863
申请日：2016-05-17
Applicant: Google LLC
Inventor： John Martinis , Nan Ding , Ryan Babbush , Sergei V. Isakov , Hartmut Neven , Vadim Smelyanskiy , Sergio Boixo Castrillo
IPC: G06N10/00
Abstract: Methods and apparatus for estimating the fidelity of quantum hardware. In one aspect, a method includes accessing a set of quantum gates; sampling a subset of quantum gates from the set of quantum gates, wherein the subset of quantum gates defines a quantum circuit; applying the quantum circuit to a quantum system and performing measurements on the quantum system to determine output information of the quantum system; calculating output information of the quantum system based on application of the quantum circuit to the quantum system; and estimating a fidelity of the quantum circuit based on the determined output information and the calculated output information of the quantum system.
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公开(公告)号：US11055626B2
公开(公告)日：2021-07-06
申请号：US16355293
申请日：2019-03-15
Applicant: Google LLC
Inventor： Ryan Babbush , Hartmut Neven
Abstract: Methods, systems, and apparatus for training quantum evolutions using sub-logical controls. In one aspect, a method includes the actions of accessing quantum hardware, wherein the quantum hardware includes a quantum system comprising one or more multi-level quantum subsystems; one or more control devices that operate on the one or more multi-level quantum subsystems according to one or more respective control parameters that relate to a parameter of a physical environment in which the multi-level quantum subsystems are located; initializing the quantum system in an initial quantum state, wherein an initial set of control parameters form a parameterization that defines the initial quantum state; obtaining one or more quantum system observables and one or more target quantum states; and iteratively training until an occurrence of a completion event.
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公开(公告)号：US12210502B2
公开(公告)日：2025-01-28
申请号：US18311733
申请日：2023-05-03
Applicant: Google LLC
Inventor： Craig Gidney , Ryan Babbush
Abstract: Methods, systems and apparatus for performing indexed operations using a unary iteration quantum circuit. In one aspect, a method includes encoding an index value in an index register comprising index qubits; encoding the index value in a control register comprising multiple control qubits; and repeatedly computing and uncomputing the control qubits to perform, conditioned on the state of the control qubits, the operation on one or more target qubits corresponding to the index value, wherein during the encoding, computing and uncomputing: the multiple control qubits are made available in sequence, and the multiple control qubits correspond to a one-hot encoding of the encoded index value.
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公开(公告)号：US20240346360A1
公开(公告)日：2024-10-17
申请号：US18510020
申请日：2023-11-15
Applicant: Google LLC
Inventor： Ryan Babbush , Joonho Lee , William Huggins
IPC: G06N10/80
CPC classification number: G06N10/80
Abstract: Methods, systems, and apparatus for simulating a quantum system. In one aspect, a method includes performing a first quantized quantum algorithm on an initial quantum state to simulate time evolution of a fermionic system and generate a time evolved quantum state; and measuring, by the quantum computer, the time evolved quantum state to obtain one or more reduced density matrices in first quantization, the measuring including performing a classical shadows method that applies separate random Clifford channels to each qubit register of multiple qubit registers that represent respective occupied orbitals in the fermionic system.
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Patent Agency Ranking
36.发明公开公开(公告)号：US20240296362A1
公开(公告)日：2024-09-05
申请号：US18574922
申请日：2022-06-28
Applicant: Google LLC
Inventor： William Huggins , Joonho Lee , Ryan Babbush
IPC: G06N10/20
CPC classification number: G06N10/20
Abstract: Methods, systems, and apparatus for hybrid quantum-classical quantum Monte Carlo. In one aspect, a method includes receiving, by a classical computer, data generated by a quantum computer, the data representing results of measurements of a trial wavefunction, wherein the trial wavefunction approximates the target wavefunction and is prepared by the quantum computer, computing, by the classical computer, a classical shadow of the trial wavefunction using the data representing the results of the measurements of the trial wavefunction, and performing, by the classical computer, imaginary time propagation for a sequence of imaginary time steps of an initial wavefunction using a Hamiltonian that characterizes the fermionic quantum system, wherein: the imaginary time propagation is performed until predetermined convergence criteria are met; and performing each imaginary time step of the imaginary time propagation comprises updating the wavefunction for the previous imaginary time step using the classical shadow of the trial wavefunction to obtain a wavefunction for the current imaginary time step.
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公开(公告)号：US20230315803A1
公开(公告)日：2023-10-05
申请号：US18313051
申请日：2023-05-05
Applicant: Google LLC
Inventor： Ryan Babbush
CPC classification number: G06F17/141 , G06N10/00 , G06E3/005 , G06F17/18 , H04L9/0852
Abstract: Methods, systems and apparatus for simulating quantum systems. In one aspect, a method includes the actions of obtaining a first Hamiltonian describing the quantum system, wherein the Hamiltonian is written in a plane wave basis comprising N plane wave basis vectors; applying a discrete Fourier transform to the first Hamiltonian to generate a second Hamiltonian written in a plane wave dual basis, wherein the second Hamiltonian comprises a number of terms that scales at most quadratically with N; and simulating the quantum system using the second Hamiltonian.
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公开(公告)号：US11675763B2
公开(公告)日：2023-06-13
申请号：US16976368
申请日：2019-04-19
Applicant: Google LLC
Inventor： Craig Gidney , Ryan Babbush
CPC classification number: G06F16/2228 , G06N10/00
Abstract: Methods, systems and apparatus for performing indexed operations using a unary iteration quantum circuit. In one aspect, a method includes encoding an index value in an index register comprising index qubits; encoding the index value in a control register comprising multiple control qubits; and repeatedly computing and uncomputing the control qubits to perform, conditioned on the state of the control qubits, the operation on one or more target qubits corresponding to the index value, wherein during the encoding, computing and uncomputing: the multiple control qubits are made available in sequence, and the multiple control qubits correspond to a one-hot encoding of the encoded index value.
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公开(公告)号：US11410071B2
公开(公告)日：2022-08-09
申请号：US16753070
申请日：2017-10-02
Applicant: Google LLC
Inventor： Ryan Babbush
Abstract: Methods, systems, and apparatus for simulating a physical system. A Hamiltonian describing the physical system is transformed into a qubit Hamiltonian describing a corresponding system of qubits, the qubit Hamiltonian comprising a transformed kinetic energy operator. The evolution of the system of qubits under the qubit Hamiltonian is simulated, including simulating the evolution of the system of qubits under the transformed kinetic energy operator by applying a fermionic swap network to the system of qubits. The simulated evolution of the system of qubits under the qubit Hamiltonian is used to determine properties of the physical system.
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公开(公告)号：US20220029639A1
公开(公告)日：2022-01-27
申请号：US17433459
申请日：2020-03-05
Applicant: Google LLC
Inventor： Jarrod Ryan McClean , Ryan Babbush , Zhang Jiang
Abstract: Methods, systems and apparatus for correcting a result of a quantum computation. In one aspect, a method includes selecting a quantum error correcting code for the quantum computation, wherein the quantum error correcting code is defined by multiple stabilizer generators; determining a set of symmetry operators, comprising: selecting a subset of the stabilizer generators, determining, for each selected stabilizer generator, a sum between an identity operator and the stabilizer generator, and multiplying the determined sums together to form a summation of terms, wherein each term in the summation is equal to a respective symmetry operator; measuring a projective correction of a physical observable over an output quantum state of the quantum computation using the determined set of symmetry operators, wherein the physical observable corresponds to the result of the quantum computation; and determining a corrected result of the quantum computation using the measured projective correction of the physical observable.
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