Fig. 3
From: Quantum-enhanced magnetometry by phase estimation algorithms with a single artificial atom
Observed scaling behavior of the flux resolution versus total sensing time for the three different metrological procedures, Kitaev (colored circles), Fourier (black diamonds) and standard (red crosses). The Kitaev algortihm has been run with constant tolerances \(\epsilon _k\) = \(\epsilon\) for each step k = 1, …, 5 and for five different values of \(\epsilon\) as indicated by different colors. The Fourier algorithm has been performed with the step-dependent tolerances \(\epsilon _k\) = 0.182, 0.076, 0.039, 0.02, 0.01 for k = 1, …, 5. We show the result of the Fourier algorithm only for the final two steps, k = 4 (filled diamonds) and k = 5 (empty diamonds), running the algorithm with four different starting delays, τ(s) = 300, 320, 340, and 360 ns (all collapsed to the same data points). The phase estimation algorithms lag behind in precision at short times when compared to the standard procedure, but rapidly gain precision at longer times. The black solid line represents the scaling law for a numerical simulation of the standard procedure with a regular passport function given by Eq. (1). The crossover to the red solid line is due to the irregularity of the passport function
