标题： 量子混沌系统中的面积定律纠缠 显示英文标题

标题： Area-Law Entanglement in Quantum Chaotic System

摘要： 纠缠熵是量子混沌的基本诊断工具，通常在混沌多体系统的高度激发本征态中表现出体积定律的尺度。 在本工作中，我们提出一个引人注目的反例：一个由弗洛凯驱动的具有类似里德伯阻塞的多体量子系统，尽管其威格纳-迪森能级统计和局部热化表明它完全混沌，但其纠缠熵却表现出严格的面积定律。 具体来说，每个弗洛凯本征态的纠缠熵被$\ln2$限制，与系统大小无关。 我们将这一异常现象归因于阻塞所施加的特定希尔伯特空间结构，这限制了分割处的施密特秩。 此外，我们通过建立受约束多体哈密顿量与中位图上的单粒子量子行走之间的对偶性，推广了这一发现，并概述了一个构造纠缠熵被预定常数限制的系统的通用方法。 我们的结果表明，仅凭纠缠熵不足以诊断多体量子混沌，并突显了希尔伯特空间几何对量子动力学和热化的重要影响。 显示英文摘要

摘要： Entanglement entropy is a fundamental diagnostic for quantum chaos, typically exhibiting volume-law scaling in highly excited eigenstates of chaotic many-body systems. In this work, we present a striking counterexample: a Floquet-driven quantum many-body system with Rydberg-like blockade that, despite being fully chaotic as indicated by its Wigner-Dyson level statistics and local thermalization, exhibits a strict area-law entanglement entropy. Specifically, the entanglement entropy of every Floquet eigenstate is bounded by $\ln2$, independent of system size. We trace this anomaly to the specific Hilbert space structure imposed by the blockades, which restricts the Schmidt rank across a bipartition. Furthermore, we generalize this discovery by establishing a duality between constrained many-body Hamiltonians and single-particle quantum walks on median graphs, and we outline a general procedure for constructing systems with an entanglement entropy bounded by a predetermined constant. Our results demonstrate that entanglement entropy alone is an insufficient diagnostic of many-body quantum chaos and highlight the profound impact of Hilbert space geometry on quantum dynamics and thermalization.