US 12,244,306 B2
Superconducting quantum circuit
Tomohiro Yamaji, Tokyo (JP); and Kohei Matsuura, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Filed by NEC Corporation, Tokyo (JP)
Filed on Dec. 28, 2022, as Appl. No. 18/090,320.
Claims priority of application No. 2022-000740 (JP), filed on Jan. 5, 2022.
Prior Publication US 2023/0216495 A1, Jul. 6, 2023
Int. Cl. G11C 5/06 (2006.01); G06N 10/40 (2022.01); H03K 17/92 (2006.01); H10N 60/12 (2023.01)
CPC H03K 17/92 (2013.01) [G06N 10/40 (2022.01); H10N 60/12 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A superconducting quantum circuit, comprising:
first to fourth qubits; and
a coupler for four-body interaction among the first to fourth qubits,
wherein the coupler includes, as a planer circuit configuration:
first and second electrodes spaced apart from a ground plane disposed surrounding peripheries of the first and second electrodes, respectively, arranged opposing to each other; and
a nonlinear element bridged between the first and second electrode, the nonlinear element including a Josephson junction,
wherein the first electrode includes
first and second opposing portions extended toward the first and second qubits, respectively from positions other than a side of the first electrode facing the second electrode,
wherein the second electrode includes:
third and fourth opposing portions extended toward the third and fourth qubits, respectively, from positions other than a side of the second electrode facing the first electrode, and
wherein 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.