AI 中文总结
该研究利用实时多体框架解析光激发关联电子系统的动量选择超快动力学，揭示电子加热的节点-反节点各向异性、反铁磁涨落的非热响应等，为相关实验提供理论解释。
AI 中文摘要
时间分辨光谱学的最新进展已能直接获取关联量子材料的动量选择非平衡动力学，揭示出电子与集体激发具有强动量依赖的响应。要解释这些观测结果，需要一个实时理论框架，该框架需一致捕捉强局域电子关联与非局域集体涨落的相互作用，而当前最先进的非平衡方法尚不具备这种能力。我们利用最新开发的实时多体框架，解析了光激发关联电子系统的动量选择超快动力学。我们预测电子加热存在瞬态节点-反节点各向异性，为时间分辨光电子能谱和拉曼实验中争论的动量依赖响应提供了微观解释，并确定了非热谱重转移，该转移是超快光电子能谱中观测到的瞬态反节点隙内态的成因。我们还发现了动量选择的磁响应，其中反铁磁涨落在远高于电子温度的情况下会经历强非热的猝灭式激发，同时保持其关联长度，之后通过动量空间磁振子级联向低动量模式弛豫。最后，通过追踪实时局域自旋极化率，我们确定了局域矩形成的动态、可实验观测的特征及其光诱导的熔化。我们的结果建立了超快电子与磁动力学的统一微观图像，为解释动量分辨泵浦-探针实验提供了框架。
英文摘要
Recent advances in time-resolved spectroscopies have enabled direct access to the momentum-selective nonequilibrium dynamics of correlated quantum materials, revealing a strongly momentum-dependent response of electrons and collective excitations. Interpreting these observations requires a real-time theoretical framework that consistently captures the interplay between strong local electronic correlations and nonlocal collective fluctuations, a capability that remains beyond state-of-the-art nonequilibrium approaches. Using a recently developed real-time many-body framework, we resolve the momentum-selective ultrafast dynamics of a photoexcited correlated electron system. We predict a transient nodal-antinodal anisotropy in electronic heating, providing a microscopic explanation for the momentum-dependent response debated in time-resolved photoemission and Raman experiments, and identify the nonthermal spectral-weight transfer responsible for the transient antinodal in-gap states observed in ultrafast photoemission. We further uncover a momentum-selective magnetic response, in which antiferromagnetic fluctuations undergo a strongly nonthermal, quench-like excitation far above the electronic temperature while preserving their correlation length, before relaxing through a momentum-space magnon cascade toward lower-momentum modes. Finally, by tracking the real-time local spin susceptibility, we identify a dynamical, experimentally accessible signature of local-moment formation and its photoinduced melting. Our results establish a unified microscopic picture of ultrafast electronic and magnetic dynamics, providing a framework for interpreting momentum-resolved pump-probe experiments.
