Fig. 1. Examples of error probabilities for the conformance test.

(A and B) Distributions of the reference process (red) P₀, and defective one (blue) P₁: the two rows present opposite and archetypal situations. The graphics (C to F) are obtained considering a pure loss channel of parameter θ = τ as the SUT, and a PC measurement. (C and D) Resulting photon number distributions p(n), in the case where a classical state is used as a probe. The overlaps between the two distributions, highlighted in green and blue, the two colors distinguishing the cases where the reference or the defective process is most likely, are visualizations of the conditional error probabilities, at a given value of τ, while their weighted sum gives an appreciation of the total error probability. (E and F) Case in which quantum probes are used: Quantum correlations enhance the performance of the discrimination task.