标题： 通过非局部测量在多体本征基中制备猫态 显示英文标题

标题： Preparation of cat states in many-body eigenbasis via non-local measurement

摘要： 工程耗散为制备原本难以通过纯单位协议访问的相关量子多体态提供了一条有前景的途径。 然而，创建具有可调特性的多个多体本征态的叠加仍然是一个主要挑战。 我们提出通过非局部后选择测量协议精确移除给定的多体福克态，从而周期性地中断多体演化。 在调节测量周期时，我们证明暗态流形在移除后仍然存在，使我们能够在长时间内过滤系统并在该流形内生成相干叠加。 作为测试平台，我们研究了一个非可积的自旋-1 XY链，该链具有可解的本征态族，这些本征态在准粒子激发方面可能有宏观差异。 我们的协议生成了这些本征态的可调叠加，包括自旋-1 Greenberger-Horne-Zeilinger态和具有可调时空序的广义变体。 在扰动下，系统表现出一个异常长寿命的亚稳态区域，其中设计的叠加保持鲁棒性。 我们的工作通过当前量子模拟器可用的工具，为通过非局部测量进行量子态制备提供了新的见解。 显示英文摘要

摘要： Engineered dissipation offers a promising route to prepare correlated quantum many-body states that are otherwise difficult to access using purely unitary protocols. However, creating superpositions of multiple many-body eigenstates with tunable properties remains a major challenge. We propose to periodically interrupt the many-body evolution by precisely removing a given many-body Fock state through a non-local post-selected measurement protocol. Upon tuning the measurement period, we show that a dark state manifold survives the removal, allowing us to filter the system and generate a coherent superposition within this manifold at long times. As a testbed, we study a non-integrable spin-1 XY chain featuring a solvable family of eigenstates that can differ macroscopically in quasi-particle excitations. Our protocol generates tunable superpositions of these eigenstates, including the spin-1 Greenberger-Horne-Zeilinger state and a generalized variant with tunable spatiotemporal order. Under perturbations, the system exhibits an exceptionally long-lived metastable regime where the engineered superpositions remain robust. Our work provides new insight into quantum state preparation via non-local measurements using tools available in current quantum simulators.