超快电子显微镜：非平衡材料研究的定量平台
Ultrafast Electron Microscopy: A Quantitative Platform for Nonequilibrium Materials Research
- University of Minnesota（明尼苏达大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文综述超快电子显微镜作为定量平台，用于研究非平衡材料中能量流动与结构演化，强调其从定性工具向定量平台的转变，并展望建立激发-功能因果链的潜力。
AI中文摘要：
宏观材料的功能不仅取决于平衡结构，还取决于载流子、声子、场、缺陷、界面和集体有序在扰动后如何动态演化。超快电子显微镜（UEM）独特地弥合了这一差距，将飞秒到纳秒的时间分辨与实空间、倒空间和能量分辨的对比度相结合。在此，我们回顾了这些集成能力如何现已成为定量地绘制电子材料中能量流动与转换的图谱，解码量子与关联系统中的电子-结构耦合，并隔离载流子、极化激元、应变和声子在光电与纳米机械架构中的局域传播。我们强调了从载流子-晶格耦合的直接计量、动量分辨的声子热化、缺陷控制的相变以及真实操作状态下的切换中涌现的预测性设计规则。我们批判性地评估了UEM从定性、概念验证实验向严谨、定量材料平台的持续成熟过程。这一范式转变正由集成多模态检测、先进能量分辨光谱、高重复频率源、多维（4D和5D）采集以及物理约束的正向建模积极推动。最终，核心机遇在于建立从初始激发到局域能量流动、瞬态结构和宏观器件功能的完整因果链。通过优先考虑定量可重复性和稳健的机制解释，UEM定位于在平衡热力学无法描述的功能状态下工程化材料。
英文摘要：
Macroscopic materials function is determined not merely by equilibrium structure, but by how carriers, phonons, fields, defects, interfaces, and collective order dynamically evolve after perturbation. Ultrafast electron microscopy (UEM) uniquely bridges this gap, coupling femtosecond-to-nanosecond timing with real-space, reciprocal-space, and energy-resolved contrast. Here, we review how these integrated capabilities now quantitatively map energy flow and conversion in electronic materials, decode electronic-structural coupling in quantum and correlated systems, and isolate the localized propagation of carriers, polaritons, strain, and phonons across optoelectronic and nanomechanical architectures. We emphasize the predictive design rules now emerging from direct metrology of carrier-lattice coupling, momentum-resolved phonon thermalization, defect-controlled phase transformations, and authentic operando switching. We critically assess UEM's ongoing maturation from a qualitative, proof-of-concept experiment into a rigorous, quantitative materials platform. This paradigm shift is actively driven by integrated multimodal detection, advanced energy-resolved spectroscopy, high-repetition-rate sources, multidimensional (4D and 5D) acquisition, and physically constrained forward modeling. Ultimately, the central opportunity lies in establishing a complete, causal link from initial excitation to localized energy flow, transient structure, and macroscopic device function. By prioritizing quantitative reproducibility and robust mechanistic interpretation, UEM is positioned to engineer materials in functional states that equilibrium thermodynamics simply cannot describe.
