Table 2 Characteristics of the two-qubit CZ gates performed between neighboring qubit pairs (Q0,Q1), (Q1,Q2), and (Q2,Q3).

gn represents the effective qubit-qubit coupling under modulation, ωm is the qubit modulation frequency, δω is the tunable qubit frequency shift under modulation, τ is the duration of the CZ gate, and ℱQPT is the two-qubit gate fidelity measured by QPT. The theoretical tunable qubit frequency shifts under modulation (δωth/2π) were obtained analytically using the experimentally determined modulation frequencies ωm and are very close to the experimentally measured values (δω/2π). The gate durations and effective qubit-qubit couplings include pulse risetimes of 40 ns to suppress the effect of pulse turn-on phase.

Qubitsgn/2π
(MHz)
ωm/2π
(MHz)
δωth/2π
(MHz)
δω/2π
(MHz)
τ
(ns)
QPT
(%)
Q0 - Q12.538327028127895
Q1 - Q21.838632333035393
Q2 - Q31.5920025725739591