We introduce protocols to prepare many-body quantum states with quantum circuits assisted by local operations and classical communication. We show that by lifting the requirement of exact preparation, one can substantially save resources. In particular, the so-called W and, more generally, Dicke states require a circuit depth and number of ancillas per site that are independent of the system size. As a by-product of our work, we introduce an efficient scheme to implement certain nonlocal, non-Clifford unitary operators. We also discuss how similar ideas may be applied in the preparation of eigenstates of well-known spin models, both free and interacting. Published by the American Physical Society 2024

中文翻译：

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用量子电路和测量逼近多体量子态


我们引入了使用量子电路在本地操作和经典通信辅助下准备多体量子态的协议。我们表明，通过取消精确准备的要求，可以大大节省资源。特别是，所谓的 W 状态和更一般的 Dicke 状态需要每个站点的电路深度和辅助数量，这与系统大小无关。作为我们工作的副产品，我们引入了一种有效的方案来实现某些非本地、非 Clifford 酉运算符。我们还讨论了如何将类似的想法应用于制备众所周知的自旋模型的特征态，包括自由和交互模型。 美国物理学会 2024 年出版