Extended Data Fig. 6. CZ gate single-particle phase calibration and benchmarking.
a, Digital circuit for global randomized benchmarking method used to calibrate single-particle phase, in which a Z rotation can be performed after each CZ gate to compensate for the acquired phase. Rrand are single-qubit rotations sampled from a Haar-random distribution and the five rotations Rf are computed to return the atom pair to the initial product state in the absence of gate errors. For the 0 CZ gates point, 20 random rotations are applied, as well as a final rotation precomputed to return population to the initial state. b, Experimental data used for calibrating the single-particle phase by optimizing the return probability P|00⟩ after 20 CZ gates (inset). For the optimal choice of ϕ, we extract a 99.48(2)% CZ gate fidelity, fitting to an exponential decay.