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arXiv 2603.05656quant-phcond-mat.stat-mechhep-th
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从算子纠缠标度看经典可模拟性

Classical Simulability from Operator Entanglement Scaling

Institut für Theoretische Physik, Universität zu Köln(科隆大学理论物理研究所)

Neil Dowling

AI总结:

通过分析局部算子纠缠的Rényi熵标度,严格证明了算子纠缠体积律导致矩阵乘积算子不可高效模拟,而对特定态类对数标度则保证可模拟,建立了量子混沌与经典可模拟性的形式化联系。

摘要:

局部算子纠缠(LOE)量化了海森堡算子的非局域结构,并作为多体混沌的诊断工具。我们提供了严格的界限,表明当算子的LOE $α$-Rényi熵具有渐近标度时,该算子何时可以被矩阵乘积算子(MPO)很好地近似。具体来说,我们证明对于$α\geq 1$的体积律标度意味着该算子不能作为MPO被高效近似,同时忠实地再现所有期望值。另一方面,如果我们限制在相关子类(系综)态上的关联,那么$α<1$熵的对数标度意味着MPO可模拟性。这一结果涵盖了相关量的范围,包括无穷温度自关联函数、时间外有序关联子以及计算基态系综上的平均情况期望值。超出这一范围,我们提供数值证据以及一个随机矩阵模型,论证这一可模拟性结果通常也适用于任意态。我们的结果巩固了低算子纠缠意味着高效张量网络可表示性的启发式预期,扩展了来自矩阵乘积态理论的著名基础结果,并提供了量子混沌与经典可模拟性之间的形式化联系。

英文摘要:

Local-operator entanglement (LOE) quantifies the nonlocal structure of Heisenberg operators and serves as a diagnostic of many-body chaos. We provide rigorous bounds showing when an operator can be well-approximated by a matrix-product operator (MPO), given asymptotic scaling of its LOE $α$-Rényi entropies. Specifically, we prove that a volume law scaling for $α\geq 1$ implies that the operator cannot be approximated efficiently as an MPO while faithfully reproducing all expectation values. On the other hand, if we restrict to correlations over a relevant sub-class of (ensembles of) states, then logarithmic scaling of the $α< 1$ entropies implies MPO simulability. This result covers a range of relevant quantities, including infinite temperature autocorrelation functions, out-of-time-ordered correlators, and average-case expectation values over ensembles of computational basis states. Beyond this regime, we provide numerical evidence together with a random matrix model to argue that this simulability result also typically holds for arbitrary states. Our results put on firm footing the heuristic expectation that a low operator entanglement implies efficient tensor network representability, extending celebrated foundational results from the theory of matrix-product states and providing a formal link between quantum chaos and classical simulability.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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