Fig. 2: Quantum correction \(N{{\mathscr{Q}}}/\parallel \Delta H\parallel\) as a function of the inverse of the process velocity v⁻¹ = N/∥ΔH∥.

The slow-driving regime v ≪ 1 corresponds to the large number of subdivisions N ≫ 1. The results of the experimental measurements (black diamonds) are shown together with the theoretical curve (solid red line) calculated for a discrete fully coherent protocol. The plot also displays the simulations of incoherent processes (blue region) obtained different dynamically varied qubit energy gaps ω_f − ω₀ = 2∥ΔH∥ and subdivisions numbers N. Finally, values of \(N{{{\mathscr{Q}}}}_{{{\rm{SPAM}}}}/\parallel \Delta H\parallel\) which would arise purely from measurement errors are also displayed (black empty circle marker). This plot shows that the experimental points have a finite separation from the region of incoherent processes (blue) and from the SPAM error region (light-purple), thus quantitatively proving that the measured quantum correction \(N{{\mathscr{Q}}}/\parallel \Delta H\parallel\) is a genuine quantum signature.