-
公开(公告)号：US20250045357A1
公开(公告)日：2025-02-06
申请号：US18921805
申请日：2024-10-21
Applicant: Google LLC
Inventor： Ryan Babbush
Abstract: Methods, systems and apparatus for estimating an expectation value of a quantum mechanical observable. In one aspect, a method includes identifying a first operator associated with the observable, wherein the first operator comprises a linear combination of terms. One or more constraints on expectation values of one or more of the terms in the linear combination are determined. A second operator is defined, wherein the second operator comprises a combination of the first operator and one or more of the determined constraints. The expectation value of the quantum mechanical observable is estimated using the second operator.
-
公开(公告)号：US20250028783A1
公开(公告)日：2025-01-23
申请号：US18906866
申请日：2024-10-04
Applicant: Google LLC
Inventor： Ryan Babbush
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.
-
公开(公告)号：US12079686B2
公开(公告)日：2024-09-03
申请号：US16975628
申请日：2019-05-10
Applicant: Google LLC
Inventor： Ryan Babbush , Jarrod Ryan McClean
IPC: G06N10/00 , H03K19/173
CPC classification number: G06N10/00 , H03K19/173
Abstract: Methods, systems and apparatus for targeting many-body states on a quantum computer. In one aspect, a method includes an adaptive phase shift method that includes preparing the quantum system in an initial state, wherein the initial state has non-zero overlap with the target eigenstate; preparing an ancilla qubit in a zero computational basis state; and iteratively applying a quantum eigenstate locking circuit to the quantum system and ancilla qubit until the state of the quantum system approximates the target eigenstate, wherein the quantum eigenstate locking circuit comprises a phase gate that, at each n-th iteration, is updated using a current average energy estimate of the quantum system.
-
公开(公告)号：US20240289659A1
公开(公告)日：2024-08-29
申请号：US18653705
申请日：2024-05-02
Applicant: Google LLC
Inventor： Ryan Babbush , Ian David Kivlichan
Abstract: Methods, systems and apparatus for performing quantum state preparation. In one aspect, a method includes the actions of defining a target quantum state of a quantum system, wherein time evolution of the quantum system is governed by a target Hamiltonian, and defining a total Hamiltonian that interpolates between an initial Hamiltonian and the target Hamiltonian, wherein the total Hamiltonian is equal to the initial Hamiltonian at an initial time and is equal to the target Hamiltonian at a final time; approximating the time evolution of the total Hamiltonian using a truncated linear combination of unitary simulations to generate a truncated time evolution operator; evolving a ground state of the initial Hamiltonian according to the truncated time evolution operator for a truncated number of time steps to generate an intermediate state; and variationally adjusting the intermediate state to determine a wavefunction that approximates the target quantum state of the quantum system.
-
公开(公告)号：US20240014829A1
公开(公告)日：2024-01-11
申请号：US18473041
申请日：2023-09-22
Applicant: Google LLC
Inventor： Jarrod Ryan McClean , Ryan Babbush , Zhang Jiang
CPC classification number: H03M13/1575 , G06N10/00
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.
-
Patent Agency Ranking
公开(公告)号：US11836575B2
公开(公告)日：2023-12-05
申请号：US17278137
申请日：2018-09-25
Applicant: Google LLC
Inventor： Ryan Babbush , Austin Greig Fowler
IPC: G06F5/16 , G06F30/20 , G06F30/337 , G06F30/373 , G06F30/398 , G06N10/40 , G06N10/60 , G06N10/00 , G06F15/16
CPC classification number: G06N10/00 , G06F15/16 , G06F30/20 , G06F30/337 , G06F30/373 , G06F30/398 , G06N10/40
Abstract: Methods, systems and apparatus for approximating a target quantum state. In one aspect, a method for determining a target quantum state includes the actions of receiving data representing a target quantum state of a quantum system as a result of applying a quantum circuit to an initial quantum state of the quantum system; determining an approximate quantum circuit that approximates the specific quantum circuit by adaptively adjusting a number of T gates available to the specific quantum circuit; and applying the determined approximate quantum circuit to the initial quantum state to obtain an approximation of the target quantum state.
-
公开(公告)号：US20230315808A1
公开(公告)日：2023-10-05
申请号：US18049207
申请日：2022-10-24
Applicant: Google LLC
Inventor： Ryan Babbush
Abstract: Methods, systems and apparatus for estimating an expectation value of a quantum mechanical observable. In one aspect, a method includes identifying a first operator associated with the observable, wherein the first operator comprises a linear combination of terms. One or more constraints on expectation values of one or more of the terms in the linear combination are determined. A second operator is defined, wherein the second operator comprises a combination of the first operator and one or more of the determined constraints. The expectation value of the quantum mechanical observable is estimated using the second operator.
-
公开(公告)号：US20230030423A1
公开(公告)日：2023-02-02
申请号：US17867182
申请日：2022-07-18
Applicant: Google LLC
Inventor： Nicholas Charles Rubin , Ryan Babbush
IPC: G06N10/20
Abstract: Methods, systems and apparatus for preparing a target quantum state of a quantum system, where the target quantum state is stationary with respect to a parameterized many-body qubit operator. In one aspect a method includes preparing an initial quantum state as an input state for a first iteration; iteratively evolving the initial quantum state and subsequent input quantum states as inputs for subsequent iterations until an approximation of the target stationary quantum state is obtained, comprising, for each iteration: computing, by quantum computation, parameter values of the many-body qubit operator for the iteration; computing, by quantum computation, an evolution time for the iteration, comprising evaluating changes in elements of a 2-RDM for the iteration; and evolving the initial quantum state or the subsequent input quantum state for the iteration using the computed parameter values and evolution time to generate a subsequent input quantum state for the subsequent iteration.
-
公开(公告)号：US11494466B2
公开(公告)日：2022-11-08
申请号：US16603964
申请日：2017-12-18
Applicant: Google LLC
Inventor： Ryan Babbush
Abstract: Methods, systems and apparatus for estimating an expectation value of a quantum mechanical observable. In one aspect, a method includes identifying a first operator associated with the observable, wherein the first operator comprises a linear combination of terms. One or more constraints on expectation values of one or more of the terms in the linear combination are determined. A second operator is defined, wherein the second operator comprises a combination of the first operator and one or more of the determined constraints. The expectation value of the quantum mechanical observable is estimated using the second operator.
-
公开(公告)号：US20220138610A1
公开(公告)日：2022-05-05
申请号：US17574192
申请日：2022-01-12
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.
-
-
-
-
-
-
-
-
-
Search Results
64
records
(took 0.025 seconds)
