公开(公告)号：US20240396194A1

公开(公告)日：2024-11-28

申请号：US18202870

申请日：2023-05-26

Applicant: Google LLC

Inventor： George Earl Grant Sterling ,  Michael C. Hamilton ,  Lev Ioffe ,  Charles Neill

IPC: H01P1/20

Abstract: A microwave filter includes a multilayer stack. The multilayer stack includes one or more first-type layers composed of a first superconductor material having a first superconducting critical temperature; and one or more second-type layers composed of a non-superconductor metal or a second superconductor material having a second superconducting critical temperature that is lower than the first superconducting critical temperature. The multilayer stack is configured to behave as a dissipative metal for photons having a frequency above twice a superconducting gap frequency of the multilayer stack and to behave as a superconductor for photons having a frequency below twice the superconducting gap frequency of the multilayer stack.

公开(公告)号：US20240370755A1

公开(公告)日：2024-11-07

申请号：US18312384

申请日：2023-05-04

Applicant: Google LLC

Inventor： Julian Shaw Kelly ,  Charles Neill

IPC: G06N10/40 ,  G06N10/20

Abstract: Methods, systems and apparatus for implementing a two-qubit quantum gate on a quantum system including a first qubit and a second qubit interacting via a coupler. In one aspect, a method includes: evolving a state of the quantum system for a predefined period of time under a Hamiltonian describing the quantum system; and performing a pulse schedule on the quantum system during evolution of its state. The pulse schedule includes: driving the quantum system with one or more baseband pulses; and driving the coupler with a parametric pulse having a center frequency greater than an average qubit anharmonicity of the first and second qubits.

公开(公告)号：US20230043001A1

公开(公告)日：2023-02-09

申请号：US17971292

申请日：2022-10-21

Applicant: Google LLC

Inventor： Charles Neill ,  Anthony Edward Megrant

IPC: H01L39/02 ,  G06N10/00 ,  H01L39/22

Abstract: Methods, systems and apparatus for implementing a tunable qubit coupler. In one aspect, a device includes: a first data qubit, a second data qubit, and a third qubit that is a tunable qubit coupler arranged to couple to the first data qubit and to couple to the second data qubit such that, during operation of the device, the tunable qubit coupler allows tunable coupling between the first data qubit and the second data qubit.

公开(公告)号：US20220358392A1

公开(公告)日：2022-11-10

申请号：US17623194

申请日：2019-10-25

Applicant: Google LLC

Inventor： Kevin Satzinger ,  Charles Neill ,  Julian Shaw Kelly ,  Andrew Dunsworth

IPC: G06N10/20 ,  G06N10/70

Abstract: Methods, systems and apparatus for benchmarking quantum computing hardware. In one aspect, a method includes defining an initial circuit configured to operate on an array of qubits, wherein the initial circuit comprises multiple instances of the two-qubit gate, wherein each instance of the two-qubit gate performs a same operation on a respective pair of neighboring qubits in the array; partitioning the initial circuit into multiple layers, wherein instances of the two-qubit gate in a respective layer can be implemented in parallel; for each of the multiple layers: constructing benchmarking circuits for the layer, wherein each benchmarking circuit for the layer comprises one or more cycles of quantum gates, each cycle comprising: the layer of instances of the two-qubit gate, and a plurality of single qubit gates; implementing the constructed benchmarking circuits to obtain experimental benchmarking data; and adjusting control parameters of the control model using the experimental benchmarking data.