Fig. 3
From: Experimental quantum verification in the presence of temporally correlated noise
RB using long-walk sequences. a, b Schematic representations of long a and short b length walks in 3D (coloured lines) and 2D (black lines), defined relative to a limit deduced from diffusive behaviour, as indicated by the blue circle. c Noise-averaged fidelity distributions of the same sequences as a function of walk length in the 2D plane. Measured infidelity vs. 2D walk length, \(\left\| {{\vec{\boldsymbol V}}_{2D}} \right\|^2\), when subject to slowly varying (grey) and rapidly varying (red) noise with linear fit overlaid. The slope of this fit is (0.8 ± 1) × 10−5, consistent with zero. d RB using long-walk sequences. Solid red line corresponds to RB performed using 20 long-walk sequences and rapidly varying noise. Extracted \(p_{{\mathrm{RB}}}^{\left( {LW} \right)}\) matches that extracted under the same conditions using an unbiased sampling of all sequences (dashed line). Grey line corresponds to RB using the same long-walk sequences and slowly varying noise. For the exponential fits, state-preparation and measurement error, κ, is fixed to 3 × 10−3
