公开(公告)号：US20210272009A1

公开(公告)日：2021-09-02

申请号：US17276668

申请日：2019-08-13

Applicant: Google LLC

Inventor： Craig Gidney ,  Ryan Babbush ,  Ian David Kivlichan

IPC: G06N10/00 ,  H03K19/20 ,  H03K19/195

Abstract: Methods, systems and apparatus for determining properties of a physical system described by an electronic structure Hamiltonian. In one aspect, a Hamiltonian describing the physical system is transformed into a qubit Hamiltonian describing a corresponding system of qubits. The qubit Hamiltonian comprises multiple two-qubit interaction terms, each comprising a respective translation invariant coefficient. The system of qubits is evolved under a unitary operator generated by the multiple two-qubit interaction terms. The evolution includes applying layers of quantum logic gates to the system of qubits, wherein each application of a layer evolves the system of qubits under a unitary operator generated by a respective subset of the multiple two-qubit interaction terms and wherein the value of the coefficients of the subset of the multiple two-qubit interaction terms that generate the unitary operator is constant. The evolved system of qubits is measured and properties of the physical system is determined.

公开(公告)号：US12175328B2

公开(公告)日：2024-12-24

申请号：US17276668

申请日：2019-08-13

Applicant: Google LLC

Inventor： Craig Gidney ,  Ryan Babbush ,  Ian David Kivlichan

IPC: G06N10/00 ,  H03K19/195 ,  H03K19/20

Abstract: Methods, systems and apparatus for determining properties of a physical system described by an electronic structure Hamiltonian. In one aspect, a Hamiltonian describing the physical system is transformed into a qubit Hamiltonian describing a corresponding system of qubits. The qubit Hamiltonian comprises multiple two-qubit interaction terms, each comprising a respective translation invariant coefficient. The system of qubits is evolved under a unitary operator generated by the multiple two-qubit interaction terms. The evolution includes applying layers of quantum logic gates to the system of qubits, wherein each application of a layer evolves the system of qubits under a unitary operator generated by a respective subset of the multiple two-qubit interaction terms and wherein the value of the coefficients of the subset of the multiple two-qubit interaction terms that generate the unitary operator is constant. The evolved system of qubits is measured and properties of the physical system is determined.

公开(公告)号：US12008433B2

公开(公告)日：2024-06-11

申请号：US16967339

申请日：2019-08-07

Applicant: Google LLC

Inventor： Ryan Babbush ,  Ian David Kivlichan

IPC: G06N10/00 ,  G06F15/16

CPC classification number: G06N10/00 ,  G06F15/16

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：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

IPC: G06N10/00 ,  G06F15/16

CPC classification number: G06N10/00 ,  G06F15/16

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：US20210174236A1

公开(公告)日：2021-06-10

申请号：US16967339

申请日：2019-08-07

Applicant: Google LLC

Inventor： Ryan Babbush ,  Ian David Kivlichan

IPC: G06N10/00 ,  G06F15/16

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.