Average fidelity estimation of twirled noisy quantum channel using unitary 2<i>t</i>-design<xref rid="cpb_28_1_010304fn1" ref-type="fn">*</xref> <fn id="cpb_28_1_010304fn1"> <label>*</label> <p>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).</p> </fn>

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).

Zhang Linxi^{1, 2, †}, Zhu Changhua¹, Pei Changxing¹

Average fidelity of the (m + 1)-stage noise circuit. In this example, we assume d = 2, n = 1, and t = 6 since the noise model is unital. The blue line is the curve fitting 1.054 × 0.9525^m. The green dotted line is the estimation of average fidelity in the case of gate-independent and weakly time-dependent noise with the lower bound on the average fidelity impact factor of the unitary error.