Quantum Error Mitigation via Matrix Product Operators

In the era of noisy intermediate-scale quantum devices, number controllable hardware qubits is insufficient to implement error correction. As an alternative, mitigation (QEM) can suppress errors in measurement results via repeated experiments and postprocessing data. Typical techniques for mitigation, e.g., quasiprobability decomposition method, ignore correlated between different gates. Here, we introduce a QEM method based on matrix product operator (MPO) representation circuit that characterize noise channel with polynomial complexity. Our technique demonstrated depth=20 fully parallel up Nq=20 undergoing local global noise. The reduced by several-times factor only small bond dimension D?=1 channel. MPO increases accuracy modeling without consuming more experimental resources, which improves performance broadens its scope application. hopeful being applied circuits higher dimensions deeper depth.6 MoreReceived 22 January 2022Accepted 10 October 2022DOI:https://doi.org/10.1103/PRXQuantum.3.040313Published American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution this work must maintain attribution author(s) published article's title, journal citation, DOI.Published SocietyPhysics Subject Headings (PhySH)Research AreasQuantum computationQuantum controlQuantum correctionTechniquesTensor network methodsQuantum Information