Fig. 4: Numerical analysis on error crafting for remnant errors.
Here we display the distribution of error rate ratio \(({q}_{x},{q}_{y},{q}_{z}):=(\frac{{p}_{x}}{p},\frac{{p}_{y}}{p},\frac{{p}_{z}}{p})\) on a plane qx + qy + qz = 1, where pa: = χaa(a ∈ {x, y, z}) is the rate of each Pauli channel in \({{\mathcal{E}}}_{{\rm{rem}}}\) and p: = px + py + pz = O(ϵ2) corresponds to the total error rate. Note that here we show results whose violation of the constraints is below threshold values (see Supplementary Notes S3 for details). The unitary synthesis is done for ϵ = 10−4 with shift factor c = 2.0, 5.0 for depolarizing and XY constraints, respectively.
