公开(公告)号：US12244305B2

公开(公告)日：2025-03-04

申请号：US17623034

申请日：2019-06-27

Applicant: Google LLC

Inventor： Daniel Thomas Sank ,  Zijun Chen

IPC: G06N10/40 ,  H03K17/92

Abstract: Methods, systems, and apparatus for measuring the dispersive shift or linewidth of a resonator coupled to a qubit. In one aspect, a method includes the actions of: generating resonator response data, comprising, for each of two computational states of the qubit: for each of multiple qubit drive frequencies: for each of multiple resonator drive frequencies: preparing the qubit in the computational state; applying a first drive pulse with the resonator drive frequency to the resonator, applying a second drive pulse with the qubit drive frequency to the qubit; measuring the state of the qubit; and processing the generated resonator response data to determine the dispersive shift or linewidth of the resonator.

公开(公告)号：US12086688B2

公开(公告)日：2024-09-10

申请号：US17748938

申请日：2022-05-19

Applicant: Google LLC

Inventor： Julian Shaw Kelly ,  Daniel Thomas Sank

IPC: G06N10/00 ,  B82Y10/00

CPC classification number: G06N10/00 ,  B82Y10/00

Abstract: Apparatus and methods for performing qubit readout. In one aspect, an apparatus includes a qubit that operates at a qubit frequency; a frequency controller that is configured to control the qubit frequency and that during a qubit measurement operation is configured to: determine a compensation pulse that when applied to the qubit, counteracts qubit frequency changes during the qubit measurement operation; and apply the determined compensation pulse to the qubit during the qubit measurement operation to maintain the qubit frequency.

公开(公告)号：US20230010205A1

公开(公告)日：2023-01-12

申请号：US17780401

申请日：2019-11-27

Applicant: Google LLC

Inventor： Daniel Thomas Sank

IPC: G06N10/40

Abstract: A detector for reading out a state of a qubit includes a flux qubit and a flux bias generator. The flux qubit includes an inductor and SQUID loop, in which the flux qubit is arranged to exhibit first and second flux states. The flux bias generator generates a first flux bias through the inductor and a second flux bias through the SQUID loop, such that, in response to a first value of the first flux bias, the energies of the first and the second flux states are substantially identical and, in response to a second value of the first flux bias, the energies of the first and the second flux states are different. In response to a first value of the second flux bias, the flux qubit couples to the qubit and, in response to a second value of the second flux bias, decouples from the qubit and suppresses tunneling.

公开(公告)号：US20220246677A1

公开(公告)日：2022-08-04

申请号：US17610241

申请日：2019-05-10

Applicant: Google LLC

Inventor： Julian Shaw Kelly ,  Anthony Edward Megrant ,  Rami Barends ,  Charles Neill ,  Daniel Thomas Sank ,  Evan Jeffrey ,  Amit Vainsencher ,  Paul Klimov ,  Christopher Michael Quintana

IPC: H01L27/18 ,  G06N10/40 ,  H01L39/22

Abstract: A quantum computing device includes: a qubit; a single XYZ control line, in which the qubit and the single control line are configured and arranged such that, during operation of the quantum computing device, the single XYZ control line allows coupling of an XY qubit control flux bias, from the single XYZ control line to the qubit, over a first frequency range at a first predetermined effective coupling strength, and coupling of a Z qubit control flux bias, from the single XYZ control line to the qubit, over a second frequency range at a second predetermined effective coupling strength.

公开(公告)号：US10650320B2

公开(公告)日：2020-05-12

申请号：US15764021

申请日：2015-09-30

Applicant: GOOGLE LLC

Inventor： Yu Chen ,  John Martinis ,  Daniel Thomas Sank ,  Alireza Shabani Barzegar

IPC: G06F13/40 ,  H01L39/02 ,  G06N10/00 ,  H01P3/00

Abstract: A qubit device includes an elongated thin film uninterrupted by Josephson junctions, a quantum device in electrical contact with a proximal end of the elongated thin film, and a ground plane that is co-planar with the elongated thin film and is in electrical contact with a distal end of the elongated thin film, in which the thin film, the quantum device, and the ground plane comprise a material that is superconducting at a designed operating temperature.