US 12,336,439 B2
Quantum gate device
Atsushi Noguchi, Koganei (JP); Alto Osada, Yokohama (JP); and Yasunobu Nakamura, Tsukuba (JP)
Assigned to JAPAN SCIENCE AND TECHNOLOGY AGENCY, Kawaguchi (JP)
Appl. No. 17/926,073
Filed by JAPAN SCIENCE AND TECHNOLOGY AGENCY, Kawaguchi (JP)
PCT Filed Apr. 8, 2021, PCT No. PCT/JP2021/014961
§ 371(c)(1), (2) Date Nov. 17, 2022,
PCT Pub. No. WO2021/235132, PCT Pub. Date Nov. 25, 2021.
Claims priority of application No. 2020-087283 (JP), filed on May 19, 2020.
Prior Publication US 2023/0189666 A1, Jun. 15, 2023
Int. Cl. G06N 10/20 (2022.01); H10N 69/00 (2023.01)
CPC H10N 69/00 (2023.02) [G06N 10/20 (2022.01)] 8 Claims
OG exemplary drawing
 
1. A quantum gate device comprising:
a) a first superconducting circuit including at least one Josephson device in an annular circuit including a superconducting wire, the first superconducting circuit being configured to resonate at a first resonance frequency;
b) a second superconducting circuit including at least one Josephson device in an annular circuit including a superconducting wire, the second superconducting circuit being configured to resonate at a second resonance frequency different from the first resonance frequency;
c) a connection unit including a capacitor and a superconducting wire provided at each of both electrodes of the capacitor, the connection unit being configured to connect the first superconducting circuit and the second superconducting circuit;
d) a magnetic field application means configured to apply a magnetic field to one or both of the first superconducting circuit and the second superconducting circuit;
e) a quantum gate control electromagnetic wave irradiation unit configured to irradiate one of the first superconducting circuit and the second superconducting circuit with a control electromagnetic wave which is an electromagnetic wave having a control frequency corresponding to an original energy difference between two energy states contributing to operation of a quantum gate among a plurality of quantized energy states formed by the first superconducting circuit and the second superconducting circuit; and
f) an unnecessary interaction suppression electromagnetic wave irradiation unit configured to irradiate one of the first superconducting circuit and the second superconducting circuit with an unnecessary interaction suppression electromagnetic wave which is an electromagnetic wave having an unnecessary interaction suppression frequency, the unnecessary interaction suppression frequency being a frequency between a first frequency and a second frequency, and differing by 10 MHz or more from a frequency corresponding to an original energy difference between arbitrarily selected two energy states among a plurality of the energy states, where the first frequency is a frequency corresponding to an original energy difference between a first energy state that is highest and a second energy state that is second highest in three energy states among a plurality of the energy states, and the second frequency is a frequency corresponding to an original energy difference between the second energy state and a third energy state having lowest energy.