发表机构
Institute of Physics, Chinese Academy of Sciences; School of Physical Sciences, University of Chinese Academy of Sciences; Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy; School of Electronic Science & Engineering, Southeast University; Department of Chemistry, New York University; Department of Chemistry, Molecular Sciences Research Hub, Imperial College London; Department of Physics, University of Hong Kong（中国科学院物理研究所; 中国科学院大学物理科学学院; 马克斯·玻恩非线性光学和超快光谱研究所; 东南大学电子科学与工程学院; 纽约大学化学系; 帝国理工学院分子科学研究中心化学系; 香港大学物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文利用合成手性光实现拓扑保护的远场手性检测，通过手性介质转换隐藏拓扑电荷，实现对映体敏感的阿秒级信号控制。
AI 中文摘要
手性在生命物质中决定分子功能，然而其光学检测仍具挑战性，因为传统手性光谱学依赖于对主导电偶极光-物质相互作用的微弱修正，使得所需光学信号微弱且脆弱。拓扑提供了一条实现鲁棒性的途径，使得可观测量的定义性质能够在无序和缺陷中幸存。然而，实验上实现用于手性光谱学的实用拓扑可观测量仍然难以捉摸。在这里，我们实现了手性拓扑光并演示了这样的可观测量。一个紧密聚焦、相位锁定、反向旋转的双色场在手性编码于三维电场轨迹中，而其主导拓扑电荷位于纵向电场分量中，在那里它隐藏于直接远场检测之外。各向同性手性介质充当拓扑换能器，将驱动场的潜在拓扑转换为传播的非线性响应，其拓扑电荷在远场中直接可观测，同时在非手性介质中被强烈抑制。使用随机取向的手性单晶粉末，我们通过发射场的拓扑电荷实验检测对映体敏感响应。该可观测量可直接在远场获取且对实验缺陷具有鲁棒性，使我们能够通过驱动双色场的相对相位在阿秒时间尺度上跟踪和控制手性信号。我们的结果确立了拓扑作为超快手性光学光谱学的实用资源。
英文摘要
Chirality underlies molecular function in living matter, yet its optical detection remains challenging because conventional chiroptical spectroscopies rely on weak corrections to the dominant electric-dipole light-matter interaction, making desired optical signals weak and fragile. Topology offers a route to robustness, enabling observables whose defining properties survive disorder and imperfections. However, experimental realization of a practical topological observable for chiral spectroscopy has remained elusive. Here we realize chiral topological light and demonstrate such an observable. A tightly focused, phase-locked, counter-rotating two-colour field encodes chirality in the three-dimensional electric-field trajectory while its dominant topological charge resides in the longitudinal electric-field component where it remains hidden from direct far-field detection. An isotropic chiral medium acts as a topological transducer, converting the latent topology of the driving field into a propagating nonlinear response whose topological charge becomes directly observable in the far field while remaining strongly suppressed in achiral media. Using randomly oriented chiral single-crystal powders, we experimentally detect the enantio-sensitive response through the topological charge of the emitted field. Directly accessible in the far field and robust against experimental imperfections, this observable allows us to track and control chiral signal on attosecond timescales through the relative phase of the driving two-colour fields. Our results establish topology as a practical resource for ultrafast chiral optical spectroscopy.
