Abstract: An oscillation apparatus includes: an oscillator including a resonator and a magnetic-field generating unit, the resonator including a loop circuit and a capacitor, the loop circuit including a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction connected in a ring shape, the magnetic-field generating unit being configured to apply a magnetic field to the loop circuit, and the oscillator being configured to perform parametric oscillation; a read-out unit for reading out an internal state of the oscillator; and a filter configured to restrict transmission of a signal in a predetermined frequency band. A circuit in which the capacitor and the loop circuit are connected in a ring shape is connected to the read-out unit through the filter.

Abstract: A sample holder includes a base comprising a support structure and a printed circuit board (PCB) in contact with the base. The PCB includes: a dielectric; a front-surface ground (GND) formed on a front surface of the dielectric; a back-surface GND formed on a back surface of the dielectric; a through hole penetrating from the front-surface GND to the back-surface GND, the through hole in which a chip is disposed, and a conductor that electrically connects the front-surface GND and the back-surface GND on an end face of the through hole. At least a part of the base below the through hole has a cavity. The support structure that supports a surface of the chip and is electrically connected to the base. The support structure is disposed in the cavity.

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 first resonator having a superconducting quantum interference device and a capacitor that forms a closed loop together with the superconducting quantum interference device; and a control line being connected to a first control port and magnetically coupled to the superconducting quantum interference device, wherein the control line includes at least a first line having a characteristic impedance that indicates a first impedance value, and a second line being provided closer to a portion magnetically coupled to the superconducting quantum interference device than the first line and having a characteristic impedance that indicates a second impedance value being different from the first impedance value.

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 sample holder includes: a pedestal made of metal; and a PCB (Printed Circuit Board) placed on the pedestal. The PCB includes a through opening that penetrates from a front surface to a rear surface of the PCB. The pedestal includes a cavity bottomed and with a top of the pedestal opened, the cavity formed at a portion corresponding to directly under the through opening on a side of the pedestal on which the PCB is placed. As a configuration on the side on which the PCB is placed, viewed from above, a part of the cavity is protruded outward from the through opening.

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 sample holder includes a base comprising a support structure and a printed circuit board (PCB) in contact with the base. The PCB includes: a dielectric; a front-surface ground (GND) formed on a front surface of the dielectric; a back-surface GND formed on a back surface of the dielectric; a through hole penetrating from the front-surface GND to the back-surface GND, the through hole in which a chip is disposed, and a conductor that electrically connects the front-surface GND and the back-surface GND on an end face of the through hole. At least a part of the base below the through hole has a cavity. The support structure that supports a surface of the chip and is electrically connected to the base. The support structure is disposed in the cavity.

Abstract: A sample holder includes a base comprising a support structure and a printed circuit board (PCB) in contact with the base. The PCB has a through hole. The PCB has a cavity in at least a part of the base below the through hole. The support structure that supports a surface of a chip and is electrically connected to the base. The support structure is disposed in the cavity. At least a part of the section supporting the chip in the support structure is not parallel to the back surface of the chip.

Abstract: A superconducting circuit and a quantum computer capable of implementing four-body interaction using a plurality of superconducting qubit circuits supplied with signals of the same frequency are provided. A superconducting circuit (1) includes four superconducting qubit circuits (10), a coupling circuit (20) directly connected to the four superconducting qubit circuits (10). Each of the superconducting qubit circuits (10) indicates a qubit by being in a first phase state or a second phase state, when the number of the superconducting qubit circuits (10) in the first phase state among the four superconducting qubit circuits (10) is an even number, an interaction term of Hamiltonian of the superconducting circuit (1) takes a first value, and when the number of the superconducting qubit circuits (10) in the first phase state among the four superconducting qubit circuits (10) is an odd number, the interaction term takes a second value.

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: An oscillation apparatus includes: an oscillator including a resonator and a magnetic-field generating unit, the resonator including a loop circuit and a capacitor, the loop circuit including a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction connected in a ring shape, the magnetic-field generating unit being configured to apply a magnetic field to the loop circuit, and the oscillator being configured to perform parametric oscillation; a read-out unit for reading out an internal state of the oscillator; and a filter configured to restrict transmission of a signal in a predetermined frequency band. A circuit in which the capacitor and the loop circuit are connected in a ring shape is connected to the read-out unit through the filter.

Abstract: An oscillation apparatus includes: an oscillator including a resonator and a magnetic-field generation unit, the resonator including a loop circuit and a capacitor, the loop circuit including a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction connected in a ring shape, the magnetic-field generation unit being configured to apply a magnetic field to the loop circuit, and the oscillator being configured to perform parametric oscillation; a read-out unit for reading out an internal state of the oscillator; and a circuit component in which a coupling strength between the oscillator and the read-out unit is variable. The oscillator is connected to the read-out unit through the circuit component.

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 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: 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 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 calibration method, a calibration apparatus, and a program capable of estimating a degree of signal loss of an input signal supplied to an oscillator are provided. The calibration method includes: outputting an input signal to be input to an oscillator to be calibrated that includes a resonator and performs parametric oscillation, from a signal generator connected to the resonator via a transmission path while sweeping a frequency or a power of this input signal; acquiring distribution data of an intensity of a reflection signal based on measurement of the intensity of the reflection signal from the oscillator in response to the input signal; and estimating a degree of signal loss by comparing the distribution data acquired by the measurement with the distribution data theoretically obtained in which a value of the degree of the signal loss of the transmission path is assumed.