AI 中文总结
本研究利用NV磁力计对YIG薄膜磁子动力学进行空间成像，通过双音混频方案分离四磁子相互作用，揭示了受驱动玻色流体的预热多代散射级联过程，确立了空间分辨磁子学作为非平衡多体动力学可视化平台的作用。
AI 中文摘要
理解相干驱动的量子多体系统在达到热平衡前如何重新分配能量，仍是多体物理学的核心挑战。本研究利用氮空位（NV）磁力计，对钇铁石榴石（YIG）薄膜中的室温磁子动力学进行微米级空间成像，分辨出构成热化过程确定性台阶的离散参量散射层级。通过双音混频方案，首先分离出基本的四磁子相互作用，并通过散射产物的空间增长提取其耦合强度；随后用近铁磁共振的强单频激发驱动系统，发现磁子-磁子相互作用会触发自发的多代散射级联，每一代中主导散射通道对应一个出射磁子处于慢磁子区域，类似慢光系统中光学非线性的增强。研究采用近场磁子学框架定量描述该动力学，并直接从功率依赖的频移中提取级联阶数与非线性系数。本研究揭示了单色注入磁子向平衡态演化的多阶段动力学过程，确立了空间分辨磁子学作为可视化非平衡多体动力学的强大平台。
英文摘要
Understanding how coherently driven quantum many-body systems redistribute energy prior to thermal equilibrium remains a central challenge in many-body physics. Here, we utilize nitrogen-vacancy (NV) magnetometry to perform micron-scale spatial imaging of room-temperature magnon dynamics in a yttrium iron garnet (YIG) thin film. We resolve a hierarchy of discrete parametric scattering events that serve as deterministic stepping stones toward thermalization. By applying a two-tone wave-mixing protocol, we first isolate the elementary four-magnon interaction and extract its coupling strength via the spatial growth of the scattering product. We then drive the system with an intense single-frequency excitation near ferromagnetic resonance, revealing that magnon-magnon interactions trigger a spontaneous, multi-generation scattering cascade. We demonstrate that in each generation, the dominant scattering channels correspond to one of the out-scattered magnons being in the slow magnon regime, reminiscent of the enhancement of optical nonlinearities in slow light systems. We capture this dynamics quantitatively using a near field magnonics framework and extract the cascade order and nonlinear coefficients directly from power-dependent frequency shifts. By revealing the multi-stage dynamical process through which monochromatic injected magnons evolve toward equilibrium, our work establishes spatially resolved magnonics as a powerful platform for visualizing non-equilibrium many-body kinetics.
