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);the Foundation of Science and Technology on Communication Networks Laboratory,China(Grant No.KX172600031)
We propose a method to estimate the average fidelity using the unitary 2t-design of a twirled noisy channel, which is suitable for large-scale quantum circuits. Compared with the unitary 2-design in randomized benchma...