公开(公告)号：US20250111259A1

公开(公告)日：2025-04-03

申请号：US18476673

申请日：2023-09-28

Applicant: Google LLC

Inventor： Matthew James McEwen

IPC: G06N10/40

Abstract: The technology provides fluorescent readout of microwave-type qubits using a paracoupler architecture. A quantum computing system comprises a set of qubits configured to be responsive to one or more microwave signals and a control apparatus configured to apply the one or more microwave signals to the set of qubits. The control apparatus includes a set of control lines configured to transmit the one or more microwave signals to corresponding ones of the set of qubits. The system also includes a readout apparatus configured to perform qubit measurements. The readout apparatus including a readout line operatively coupled to the qubits. A paracoupler operatively arranged between the set of qubits and the readout apparatus is configured to enable parametric fluorescent readout of the qubits via the readout apparatus. When the paracoupler is not driven it prevents coupling of the qubits with the readout line.

公开(公告)号：US20250068959A1

公开(公告)日：2025-02-27

申请号：US18941942

申请日：2024-11-08

Applicant: Google LLC

Inventor： Kevin Chenghao Miao ,  Alexander Korotkov ,  Matthew James McEwen ,  Rami Barends

IPC: G06N10/70 ,  G06N10/40

Abstract: Methods, systems and apparatus for resetting a qubit. In one aspect, an apparatus includes a qubit, wherein the state of the qubit occupies a plurality of levels comprising two computational levels and one or more non-computational levels; a resonator that operates at a resonator frequency; control electronics that control a frequency of the qubit such that during a reset operation the qubit frequency is adjusted from a holding frequency that is lower than the resonator frequency to an idling frequency that is higher than the resonator frequency, and during the adjustment a first derivative of the qubit frequency at a first time is positive, at a second time that occurs after the first time is zero, and at a third time that occurs after the second time is positive, where the qubit frequency achieves the idling frequency at a fourth time that occurs after the third time.

公开(公告)号：US12008435B2

公开(公告)日：2024-06-11

申请号：US17694820

申请日：2022-03-15

Applicant: Google LLC

Inventor： Alexander Nikolaevich Korotkov ,  Kevin Joseph Satzinger ,  Matthew James McEwen ,  Vadim Smelyanskiy ,  Paul Victor Klimov ,  Rami Barends ,  Julian Shaw Kelly ,  Juan Carlos Atalaya-Chavez ,  Zijun Chen

IPC: G06N10/70 ,  G06N10/40

CPC classification number: G06N10/40

Abstract: A quantum computing system configured for removal of leakage states can include quantum hardware including a first qubit and a second qubit, wherein the first qubit is configured to have a first transition frequency and wherein the second qubit is configured to have a second transition frequency, the first transition frequency being greater than the second transition frequency. The quantum computing system can include one or more quantum control devices configured to control operation of at least the first qubit and the second qubit, wherein the one or more quantum control devices are configured to implement a quantum gate operation on the first qubit and the second qubit based at least in part on the first transition frequency and the second transition frequency, and wherein the one or more quantum control devices are configured to periodically reset a quantum state of the first qubit.

公开(公告)号：US12141661B2

公开(公告)日：2024-11-12

申请号：US18305152

申请日：2023-04-21

Applicant: Google LLC

Inventor： Kevin Chenghao Miao ,  Alexander Korotkov ,  Matthew James McEwen ,  Rami Barends

IPC: G06N10/70 ,  G06N10/40

Abstract: Methods, systems and apparatus for resetting a qubit. In one aspect, an apparatus includes a qubit, wherein the state of the qubit occupies a plurality of levels comprising two computational levels and one or more non-computational levels; a resonator that operates at a resonator frequency; control electronics that control a frequency of the qubit such that during a reset operation the qubit frequency is adjusted from a holding frequency that is lower than the resonator frequency to an idling frequency that is higher than the resonator frequency, and during the adjustment a first derivative of the qubit frequency at a first time is positive, at a second time that occurs after the first time is zero, and at a third time that occurs after the second time is positive, where the qubit frequency achieves the idling frequency at a fourth time that occurs after the third time.

公开(公告)号：US20240144069A1

公开(公告)日：2024-05-02

申请号：US18495547

申请日：2023-10-26

Applicant: Google LLC

Inventor： Matthew James McEwen ,  Craig Gidney

IPC: G06N10/70 ,  G06N10/40

CPC classification number: G06N10/70 ,  G06N10/40

Abstract: Methods, systems, and apparatus for implementing a quantum circuit that moves a surface code patch of qubits. In one aspect, a method includes performing a first surface code cycle in a system of measure and data qubits. A first CNOT gate is applied to a measure qubit and a first data qubit, where the first data qubit is coupled to the measure qubit in a first direction and the first CNOT gate targets one of the measure qubits and the first data qubit. A second CNOT gate is applied to the measure qubit and the first data qubit, where the second CNOT gate targets another of the measure qubit and the first data qubit. Performing the first surface code cycle transfers information stored by the measure qubit and information stored by the first data qubit to other qubits to logically move the measure qubit and the first data qubit.

公开(公告)号：US20230342651A1

公开(公告)日：2023-10-26

申请号：US18305174

申请日：2023-04-21

Applicant: Google LLC

Inventor： Kevin Chenghao Miao ,  Alexander Korotkov ,  Matthew James McEwen ,  Rami Barends ,  Juan Carlos Atalaya Chavez

IPC: G06N10/70 ,  G06N10/40

CPC classification number: G06N10/70 ,  G06N10/40

Abstract: Methods, systems and apparatus for transporting data qubit leakage. In one aspect, an apparatus includes, for a data qubit that has been operated on by a quantum computing system to place the data qubit in a first state, wherein the first state encodes logical information: preparing, by the quantum computing system, an ancilla qubit in a known initial state; and performing, by the quantum computing system, a leakage transport operation using one or more two-qubit gates on the data qubit and the ancilla qubit to transfer leakage from the data qubit to the ancilla qubit.

公开(公告)号：US20220414514A1

公开(公告)日：2022-12-29

申请号：US17694820

申请日：2022-03-15

Applicant: Google LLC

Inventor： Alexander Nikolaevich Korotkov ,  Kevin Joseph Satzinger ,  Matthew James McEwen ,  Vadim Smelyanskiy ,  Paul Victor Klimov ,  Rami Barends ,  Julian Shaw Kelly ,  Juan Carlos Atalaya-Chavez ,  Zijun Chen

IPC: G06N10/40

Abstract: A quantum computing system configured for removal of leakage states can include quantum hardware including a first qubit and a second qubit, wherein the first qubit is configured to have a first transition frequency and wherein the second qubit is configured to have a second transition frequency, the first transition frequency being greater than the second transition frequency. The quantum computing system can include one or more quantum control devices configured to control operation of at least the first qubit and the second qubit, wherein the one or more quantum control devices are configured to implement a quantum gate operation on the first qubit and the second qubit based at least in part on the first transition frequency and the second transition frequency, and wherein the one or more quantum control devices are configured to periodically reset a quantum state of the first qubit.