Average fidelity estimation of twirled noisy quantum channel using unitary 2t-design Project supported by the National Natural Science Foundation of China (Grant Nos. 61372076 and 61701375), the 111 Project, China (Grant No. B08038), the Key Research and Development Plan of Shannxi Province, China (Grant No. BBD24017290001), and the Foundation of Science and Technology on Communication Networks Laboratory, China (Grant No. KX172600031). |
A CPTP quantum channel for any dn-dimensional input density operator ρ = |ψ⟩ ⟨ψ|. |