Nec Corporation

Tomohiro Yamaji

Tsuyoshi Yamamoto

Yoshihito Hashimoto

Hideyuki Satou

Kohei Matsuura

Katsumi Kikuchi

Suguru Watanabe

Takanori Nishi

Aiko Yamaguchi

Aiko Uchiyama

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 () is flip-chip mounted on an interposer () by a bump (). A coplanar line () coupling adjacent quantum bits is formed on the quantum chip (). A gap () is provided, in the interposer (), at a location facing a center conductor () of the coplanar line (). A second ground electrode () is formed around gap (). The interposer () has a connection electrode () connecting the second ground electrode () around the gap (). A bump (A) formed in the vicinity of the connection electrode () is connected to the first ground electrode () and the second ground electrode ().

Quantum device and quantum computer

Provided are an oscillator and a quantum computer capable of suppressing an occupied area of a circuit. An oscillator () includes a resonator () including a plurality of loop circuits in which a first superconducting line (), a first Josephson junction (), a second superconducting line (), and a second Josephson junction () are annularly connected, and a magnetic field application circuit () 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.

Oscillator and quantum computer

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.

Superconducting quantum circuit

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.

Semiconductor device

A superconducting quantum circuit apparatus, including: two or four Josephson parametric oscillators, JPOs, each including: a SQUID; and a pump line, with a pump signal supplied thereto, providing a magnetic flux penetrating through the loop of the SQUID, the JPOs oscillating parametrically in response to the pump signal supplied to the pump line; a coupler to couple the two or four JPOs; and a phase adjuster that varies a relative phase between or among pump signals supplied respectively to the pump lines of the two or four JPOs for parametric oscillation, to vary a strength of a two-body or four-body interaction.

Superconducting quantum circuit apparatus and control method for a super conducting quantum circuit

A resonator, an oscillator, and a quantum computer in which the area occupied by the circuit can be reduced is provided. A resonator () includes a 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, and a capacitor (). The capacitor () and the loop circuit () are connected in a ring shape.

Resonator, oscillator, and quantum computer

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.

Holder, quantum device, and manufacturing method of quantum device

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.

Oscillator

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.

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Tokyo, Japan

Tomohiro Yamaji