Fig. 1: Incoherent and coherent algorithms.
From: On the query complexity of unitary channel certification
a Incoherent algorithm. The double line represents the classical registers. b Coherent algorithm. \({{\mathcal{C}}}_{k}\) for 1 ≤ k ≤ N represents a CPTP map that we apply at k-th step as part of the algorithm. We allow arbitrarily large ancillary systems for both algorithms.
