[15a-K406-1~11] KS.2 Quantum Information Engineering Group

9:30 AM - 9:45 AM JST(12:30 AM - 12:45 AM UTC)

[15a-K406-3] Calculation of participation ratio around junction wire of superconducting transmon qubit

〇Yoshihito Hashimoto¹, Tsuyoshi Yamamoto¹, Yohei Kawakami¹ (1.NEC Corporation)

Keywords:

qubit,superconductor,dielectric loss

Participation ratio (PR) around a junction wire of a superconducting transmon qubit is calculated using electromagnetic simulator, and the obtained PR is compared with an analytical formula. Simulation result of the PR of metal-air (MA) interface layer is 5.1 times greater than the value predicted by the analytic formula. The origin of this large difference is that the formula does not take into account a phenomenon that electric field on the lower side of the junction wire is stronger than that on the upper side. If the PR predicted by the formula is corrected by taking this phenomenon into account, the simulation result of the PR of MA interface layer is only 1.16 times greater than the corrected value. It means that the simulation result is reasonable.