Accurate and bounded approximation of quantum correlation functions

Abstract:The exact classical simulation of non-integrable quantum systems rapidly becomes intractable beyond small system sizes, yet its role is central to predicting many-body dynamics. Approximate methods alleviate this cost but typically lack rigorous guarantees on their deviation from the exact result. For the infinite-temperature correlation function, we derive a rigorous error bound for approximating the full dynamics within a computable finite-sized region. Applied to autocorrelations, this finite-region approach is especially accurate across one-dimensional systems and beyond, and can further provide rigorous error bounds for other approximate methods, demonstrated here for matrix-product-operator simulations.

arXiv:2609.35114 [quant-ph]

(or arXiv:2609.35114v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2609.35114 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

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