公开(公告)号：US12184339B2

公开(公告)日：2024-12-31

申请号：US17790819

申请日：2020-12-28

Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY

Inventor： Shingo Kono ,  Yasunobu Nakamura

IPC: H04B10/70 ,  G06N10/40 ,  G21K1/00

Abstract: A microwave photon control device includes a first qubit and a second qubit that are connected in parallel to a waveguide through which microwave photons propagate, and a direct coupling between the first qubit and the second qubit. An interval between the first qubit and the second qubit is (¼+n/2) times as long as a wavelength of microwave photons (where n is an integer equal to or larger than 0). A quantum entangled state is formed between the first qubit and the second qubit. The direct coupling cancels out a coupling via the waveguide between the first qubit and the second qubit. By a relaxation rate of the first qubit and the second qubit, and a phase of the quantum entangled state being controlled, the microwave photon control device operates while switching between a first operation mode, a second operation mode, and a third operation mode.

公开(公告)号：US12178143B2

公开(公告)日：2024-12-24

申请号：US18224685

申请日：2023-07-21

Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY

Inventor： Yasunobu Nakamura ,  Yutaka Tabuchi ,  Shuhei Tamate

IPC: H10N69/00 ,  G06N10/00 ,  H10N60/12 ,  H10N60/80

Abstract: A superconducting complex quantum computing circuit includes a circuit substrate in which a wiring pattern of a circuit element including quantum bits and measurement electrodes, and ground patterns are formed, and through-electrodes connecting the ground pattern formed on a first surface of the substrate surface and the ground pattern formed on a second surface; a first ground electrode including a first contact portion in contact with the ground patterns, and a first non-contact portion having a shape corresponding to a shape of the wiring pattern; a second ground electrode including a second contact portion in contact with the ground pattern; a control signal line provided with a contact spring pin at a tip; and a pressing member that presses the first ground electrode against the first surface of the circuit substrate or presses the second ground electrode against the second surface of the circuit substrate.

公开(公告)号：US12212295B2

公开(公告)日：2025-01-28

申请号：US17295577

申请日：2019-11-22

Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY

Inventor： Yasunobu Nakamura ,  Shingo Kono ,  Kazuki Koshino

IPC: H03H11/04 ,  G06N10/00 ,  H10N60/12

Abstract: This nonlinear microwave filter is provided with quantum bits that are formed on a circuit board in which target quantum bits are formed which are quantum bits controlled in a superconducting quantum circuit, and that are coupled to a control waveguide to which the target quantum bits are coupled, wherein the distance to a waveguide end in the control waveguide is within a predetermined range from semi integer times the resonant wavelength, the quantum bits have a resonant frequency in which the difference from the resonant frequency of the target quantum bits is within a predetermined range, and the coupling to the control waveguide is stronger by a predetermined value than the coupling between the target quantum bits and the control waveguide.

公开(公告)号：US12099902B2

公开(公告)日：2024-09-24

申请号：US17629718

申请日：2020-02-28

Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY

Inventor： Atsushi Noguchi ,  Yasunobu Nakamura

IPC: G06N10/40 ,  G06N10/20 ,  H10N60/12

CPC classification number: G06N10/40 ,  G06N10/20 ,  H10N60/12

Abstract: A quantum gate device includes a first superconducting circuit which resonates at a first resonance frequency, second superconducting circuit which resonates at a second resonance frequency, and connector which connects these circuits. The first superconducting circuit includes a single first Josephson device, second Josephson device group, and first capacitor. The second Josephson device group includes n Josephson devices connected by a line made of a superconductor. The Josephson energy possessed by each of the n Josephson devices is greater than n times that of the first Josephson device. The quantum gate device further includes a magnetic field applier which applies a static magnetic field to the partial superconducting circuit, and an electromagnetic wave irradiator (first electromagnetic wave irradiator) which irradiates the first superconducting circuit and/or second superconducting circuit with an electromagnetic wave having a difference frequency which is equal to the difference between the first and second resonance frequencies.

公开(公告)号：US11758829B2

公开(公告)日：2023-09-12

申请号：US17283037

申请日：2019-10-31

Applicant: JAPAN SCIENCE AND TECHNOLOGY AGENCY

Inventor： Yasunobu Nakamura ,  Yutaka Tabuchi ,  Shuhei Tamate

IPC: H10N69/00 ,  G06N10/00 ,  H10N60/12 ,  H10N60/80

CPC classification number: H10N69/00 ,  G06N10/00 ,  H10N60/12 ,  H10N60/805

Abstract: A superconducting complex quantum computing circuit includes a circuit substrate in which a wiring pattern of a circuit element including quantum bits and measurement electrodes, and ground patterns are formed, and through-electrodes connecting the ground pattern formed on a first surface of the substrate surface and the ground pattern formed on a second surface; a first ground electrode including a first contact portion in contact with the ground patterns, and a first non-contact portion having a shape corresponding to a shape of the wiring pattern; a second ground electrode including a second contact portion in contact with the ground pattern; a control signal line provided with a contact spring pin at a tip; and a pressing member that presses the first ground electrode against the first surface of the circuit substrate or presses the second ground electrode against the second surface of the circuit substrate.