发表机构
ETH Zürich; IBM Research; University of Edinburgh; National University of Singapore（苏黎世联邦理工学院; IBM研究院; 爱丁堡大学; 新加坡国立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出分布式量子优势的三个条件（可承受拼接、经典难度保持、梯度可解析），并证明有界接口的有限局域深度电路可满足，通过IBM处理器上的环面码实验验证了可行性。
AI 中文摘要
电路切割在比电路更小的处理器上运行量子计算，其代价是经典拼接，而拼接成本随切割门数量呈指数增长。保持这一成本可承受对于实现优势是必要的但并非充分条件，因为拼接经典上容易的子电路本身也是经典上容易的。我们在给定预算下提出了分布式量子优势的三个要求：可承受的拼接、在切割后仍然存在的经典难度，以及对于变分电路而言，可解析的梯度。我们证明，在所述假设下，当子电路在有界接口后增长时，拼接保持可承受，而当固定宽度的子电路倍增时，拼接变得指数昂贵。我们将这些要求转化为筛选标准，并将其应用于十八个电路族。我们确定了具有有界接口的有限局域深度电路作为这些要求可以共存的环境，其难度仅在最坏情况下得到确立。作为经典可验证的原理验证，我们在IBM Nighthawk处理器上拼接了一个连接两个场扰动环面码补丁的门，最多涉及142个自旋，并确认重建至少可以解析超出独立执行范围的接触关联，最多可达98个量子比特。
英文摘要
Circuit cutting runs a quantum computation on processors smaller than the circuit, at the price of classical knitting whose cost grows exponentially with the number of cut gates. Keeping this cost affordable is necessary but not sufficient for an advantage, since knitting classically easy subcircuits is itself classically easy. We formulate three requirements for distributed quantum advantage under a stated budget: affordable knitting, classical difficulty that survives the cut, and, for variational circuits, resolvable gradients. We prove that under stated assumptions knitting stays affordable when subcircuits grow behind a bounded interface and becomes exponentially expensive when fixed-width subcircuits multiply. We turn the requirements into screening criteria and apply them to eighteen circuit families. We identify finite local-depth circuits with bounded interfaces as a setting in which the requirements can coexist, with hardness established only in the worst case. As a classically verifiable proof of principle, we knit one gate joining two field-perturbed toric-code patches on an IBM Nighthawk processor for up to 142 spins, and confirm that the reconstruction can at least resolve the contact correlation beyond independent execution for up to 98 qubits.
Comments14 pages of main text + 25 pages of appendices; 18 figures, 7 tables
