Thresholds in the Robustness of Error Mitigation in Noisy Quantum Dynamics

TitleThresholds in the Robustness of Error Mitigation in Noisy Quantum Dynamics
Publication TypeJournal Article
Year of Publication2023
AuthorsNiroula, P, Gopalakrishnan, S, Gullans, MJ
Date Published10/30/2023

Extracting useful information from noisy near-term quantum simulations requires error mitigation strategies. A broad class of these strategies rely on precise characterization of the noise source. We study the robustness of such strategies when the noise is imperfectly characterized. We adapt an Imry-Ma argument to predict the existence of a threshold in the robustness of error mitigation for random spatially local circuits in spatial dimensions D≥2: noise characterization disorder below the threshold rate allows for error mitigation up to times that scale with the number of qubits. For one-dimensional circuits, by contrast, mitigation fails at an O(1) time for any imperfection in the characterization of disorder. As a result, error mitigation is only a practical method for sufficiently well-characterized noise. We discuss further implications for tests of quantum computational advantage, fault-tolerant probes of measurement-induced phase transitions, and quantum algorithms in near-term devices.