Abstract: An oscillator in which crosstalk can be reduced is provided. An oscillator includes a SQUID, a transmission line connected to the SQUID, a ground plane, and a first connection circuit disposed in a vicinity of a node of an electric field of a standing wave that is generated when the oscillator is oscillating, the first connection circuit connecting parts of the ground plane located on both sides of the transmission line to each other.

Abstract: A resonator, an oscillator, and a quantum computer capable of preventing oscillation conditions for generating a parametric oscillation from becoming complicated are provided. A resonator includes at least one loop circuit in which a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction are connected in a ring shape, in which critical current values of the first and second Josephson junctions are different from each other.

Abstract: A superconducting quantum circuit apparatus includes first through fourth qubits; and a coupler arranged in a region surrounded by a ground plane. The coupler includes: first and second electrodes opposed to each other; and a nonlinear element including at least one Josephson junction bridged between the first electrode and the second electrode between the first and second electrode, the first electrode including first and second opposing portions extended toward the first and second qubits, the second electrode including third and fourth opposing portions extended toward third and fourth qubit, the first through fourth opposing portions having ends for capacitive coupling with the first through fourth qubits, respectively. The ends of the first through fourth opposing portions are disposed within the region surrounded by the ground plane.

Abstract: An oscillator in which crosstalk can be reduced is provided. An oscillator includes a SQUID, a transmission line connected to the SQUID, a ground plane, and a first connection circuit disposed in a vicinity of a node of an electric field of a standing wave that is generated when the oscillator is oscillating, the first connection circuit connecting parts of the ground plane located on both sides of the transmission line to each other.

Abstract: Provided are an oscillator and a quantum computer capable of suppressing an occupied area of a circuit. An oscillator (300) includes a resonator (100) including a plurality of loop circuits in which a first superconducting line (112a), a first Josephson junction (111a), a second superconducting line (112b), and a second Josephson junction (111b) are annularly connected, and a magnetic field application circuit (200) including an electrode that goes around in a predetermined shape and configured to apply a magnetic field to the loop circuit, in which the electrode is arranged so as to face at least two of the loop circuits.

Abstract: Provided is a quantum device capable of suppressing reduction in performance of quantum bit even when a quantum chip is flip-chip mounted on an interposer. A quantum chip (10) is flip-chip mounted on an interposer (20) by a bump (30). A coplanar line (12) coupling adjacent quantum bits is formed on the quantum chip (10). A gap (22) is provided, in the interposer (20), at a location facing a center conductor (12a) of the coplanar line (12). A second ground electrode (24) is formed around gap (22). The interposer (20) has a connection electrode (40) connecting the second ground electrode (24) around the gap (22). A bump (30A) formed in the vicinity of the connection electrode (40) is connected to the first ground electrode (12b) and the second ground electrode (24).

Abstract: A coupler includes first and second electrodes and a nonlinear element including a Josephson junction. The first and second electrodes are spaced apart from a ground plane surrounding peripheries thereof and arranged opposed to each other. The first/second electrode includes two opposing portions extended toward first and second qubits/third and fourth qubits. At least either one of a gap between the first electrode and the ground plane facing the first electrode and a gap between the second electrode and the ground plane facing the second electrode, includes a gap width of at least a value of a same extent as or a fraction of a size of the first electrode or the second electrode.

Abstract: An oscillator in which crosstalk can be reduced is provided. An oscillator includes a SQUID, a transmission line connected to the SQUID, a ground plane, and a first connection circuit disposed in a vicinity of a node of an electric field of a standing wave that is generated when the oscillator is oscillating, the first connection circuit connecting parts of the ground plane located on both sides of the transmission line to each other.

Abstract: A superconducting quantum circuit includes a plurality of SQUIDs (Superconducting Quantum Interference Devices) connected in parallel, each of the plurality of SQUIDs including a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction connected in a loop, wherein a junction area of the first Josephson junction and a junction area of the second Josephson junction are different from each other, the plurality of SQUIDs configured to be mutually different in either one or both of: a sum of the junction area of the first Josephson junction and the junction area of the second Josephson junction; and a ratio of the junction area of the first Josephson junction to the junction area of the second Josephson junction.

Abstract: A resonator, an oscillator, and a quantum computer in which both moderate nonlinearity and a low loss are achieved, and the area occupied by the circuit can be reduced are provided. A resonator (100) includes at least one loop circuit (110) in which a first superconducting line (101), a first Josephson junction (103), a second superconducting line (102), and a second Josephson junction (104) are connected in a ring shape, at least one third Josephson junction (130) provided separately from the Josephson junction included in the loop circuit (110), and a capacitor (120), in which the loop circuit (110), the third Josephson junction (130), and the capacitor (120) are connected in a ring shape.

Abstract: A resonator, an oscillator, and a quantum computer in which the area occupied by the circuit can be reduced is provided. A resonator (100) includes a loop circuit (110) in which a first superconducting line (101), a first Josephson junction (103), a second superconducting line (102), and a second Josephson junction (104) are connected in a ring shape, and a capacitor (120). The capacitor (120) and the loop circuit (110) are connected in a ring shape.

Abstract: An oscillator in which crosstalk can be reduced is provided. An oscillator includes a SQUID, a transmission line connected to the SQUID, a ground plane, and a first connection circuit disposed in a vicinity of a node of an electric field of a standing wave that is generated when the oscillator is oscillating, the first connection circuit connecting parts of the ground plane located on both sides of the transmission line to each other.

Abstract: An oscillator in which crosstalk can be reduced is provided. An oscillator includes a ground plane made of a superconductor, a conductive member spaced apart from and surrounded by the ground plane, a SQUID of which one end is connected to the conductive member and the other end is connected to the ground plane, a first connection circuit made of a superconductor, connecting parts of the ground plane located on both sides of a vicinity of a connection part between the conductive member and the SQUID to each other, and a superconducting loop circuit surrounding the SQUID and using the ground plane and the first connection circuit.

Abstract: A circuit manufacturing method according to the present disclosure is a circuit manufacturing method by deposition, comprising performing first deposition for forming a first superconductor layer, oxidizing a surface of the first superconductor layer to form an oxide film, performing second deposition for forming a second superconductor layer, whereby a circuit in which Josephson junctions are aligned is generated. A mask includes two opening parts and an odd number of first-type opening parts. The width of a first-type opening part has such a length that the area of a Josephson junction formed based on the first superconductor layer and the second superconductor layer derived from the first-type opening part becomes larger than the area of a Josephson junction formed based on the first superconductor layer and the second superconductor layer derived from the two opening parts that are adjacent to each other.

Abstract: A quantum device includes a quantum chip and a holder. The holder includes a pedestal, a recess portion formed in a main surface of the pedestal so as to be opposed to the quantum chip, and a suction tube provided such that in the recess portion, a suction opening is positioned in a bottom surface of the quantum chip.

Abstract: A resonator, an oscillator, and a quantum computer capable of preventing oscillation conditions for generating a parametric oscillation from becoming complicated are provided. A resonator includes at least one loop circuit in which a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction are connected in a ring shape, in which critical current values of the first and second Josephson junctions are different from each other.

Abstract: A seat attitude control apparatus for adjusting a seat with respect to forward/backward position, reclining angle and others so that the attitudes of the seat appropriate to the figures of a plurality of specified occupants can be realized individually and separately. Seat attitude data thus obtained are registered in a microcomputer so as to be utilized for controlling the seat attitude appropriate to the actual occupant as specified, as occasion requires. The seat attitude data is erasble and fresh seat attitude data can be registered for another occupant. The seat attitude control is performed with the aid of one memory switch and four control switches disposed in an array convenient for manipulation.