AI 中文总结
本研究探究非局域三波混频系统的动力学，发现其全局能级统计具可积性但本征态遍历离域，归因于运动学约束导致的希尔伯特空间碎片化，后期OTOC缩放为三体瓶颈提供实验标志。
AI 中文摘要
理解多体系统中量子热化与局域化的边界，仍是凝聚态物理和量子信息科学的核心前沿。本工作研究具有长程三体相互作用的通用模型（即非局域三波混频系统）的动力学与谱性质，该模型近期已通过一端接超导量子比特镜的微波法布里-珀罗腔实现。利用精确对角化技术，我们揭示了一个显著悖论：全局能级间距统计显示可积性，尽管所有动力学可观测量和本征态的逆参与率表明遍历性与离域化。我们证明该行为是运动学约束驱动的强希尔伯特空间碎片化的标志，而非显式全局对称性。在这些子空间内，动力学通过迟滞有序关联子（OTOC）快速混乱，而全局输运受严重瓶颈，导致向平衡态的对数弛豫。相同能量下本征态纠缠熵的波动进一步证实了这一图像。最后，我们证明后期OTOC平均值随系统尺度缩放，为潜在三体运动学瓶颈提供了独特的实验可观测标志。
英文摘要
Understanding the boundaries between quantum thermalization and localization in many-body systems remains a central frontier of condensed matter and quantum information science. In this work, we investigate the dynamics and spectral properties of a generic model with long-range three-body-interaction, namely, a system with non-local three-wave-mixing. This model has been realized recently with a microwave Fabry-Perot cavity terminated on one end by a superconducting qubit mirror. Utilizing exact diagonalization techniques, we uncover a striking paradox: the global energy level spacing statistics show integrability, even though all dynamic observables and inverse participation ratios of the eigenstates indicate ergodicity and delocalization. We show that this behavior is a hallmark of strong Hilbert space fragmentation driven by kinematic constraints rather than an explicit global symmetry. Inside these sectors, dynamics scramble rapidly, as evidenced by the out-of-time-ordered correlator (OTOC), while global transport is heavily bottlenecked, resulting in a logarithmic relaxation to equilibrium. This picture is further confirmed by fluctuations in eigenstate entanglement entropy at the same energy. Finally, we demonstrate that the late time OTOC average scales with system size, providing a distinct experimentally accessible signature of the underlying three-body kinetic bottlenecks.
Comments11 pages, 5 figures
