发表机构
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences; Department of Applied Physics, KTH Royal Institute of Technology（中国科学院物理研究所凝聚态物理国家实验室; 瑞典皇家理工学院应用物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过时间分辨光电子能谱证实2H-NbSe2体态金属能带可被Floquet修饰，利用相干Floquet-Volkov干涉解释偏振依赖的副本重分配，为操控金属输运和集体电子相提供新途径。
AI 中文摘要
Floquet修饰提供了一条通过周期性光学驱动来控制电子态的途径。其在固体中的实现主要集中在拓扑绝缘体表面态、半导体和二维狄拉克半金属上。将这种控制扩展到体态金属，将能够操纵金属输运和集体序所依托的巡游态。然而，强屏蔽和快速散射长期以来使人们对其在体态金属中的可行性存疑，而光电子修饰又使其识别复杂化。在此，我们利用时间分辨和角分辨光电子能谱，识别了2H-NbSe2中重叠的、源自体态的金属能带的Floquet修饰。在稀疏的未占据态窗口中，光子位移的副本保留了母能带的色散关系，并且仅在泵浦-探测重叠期间出现。在固定探测偏振的情况下旋转泵浦光的线性偏振，会在动量空间分支之间重新分配副本权重。使用一组通用参数，一个考虑固体内部和外部光场的模型，通过相干Floquet-Volkov干涉捕捉了这种重新分配，其吻合度优于单独考虑任一途径或它们的非相干强度之和。这些发现将Floquet修饰扩展到多带金属的巡游体态能带，且不依赖于观察母能带与其光子修饰副本之间杂化所打开的能隙，为探索相干光学修饰如何与金属输运和集体电子相耦合提供了基础。
英文摘要
Floquet dressing offers a route to controlling electronic states through periodic optical driving. Its realization in solids has centred primarily on topological-insulator surface states, semiconductors and two-dimensional Dirac semimetals. Extending this control to bulk metals would enable manipulation of the itinerant states underlying metallic transport and collective order. Yet strong screening and rapid scattering have long cast doubt on its feasibility in bulk metals, while photoelectron dressing complicates its identification. Here we identify Floquet dressing of the overlapping, bulk-derived metallic bands of 2H-NbSe2 using time- and angle-resolved photoemission spectroscopy. Photon-shifted replicas in a sparse unoccupied-state window retain the parent-band dispersions and appear only during pump--probe overlap. Rotating the pump's linear polarization at fixed probe polarization redistributes replica weight between momentum-space branches. With a common parameter set, a model accounting for the optical fields inside and outside the solid captures this redistribution through coherent Floquet--Volkov interference more closely than either pathway alone or their incoherent intensity sum. These findings extend Floquet dressing to the itinerant bulk bands of a multiband metal without relying on the observation of energy gaps opened by hybridization between parent bands and their photon-dressed replicas, providing a basis for exploring how coherent optical dressing couples to metallic transport and collective electronic phases.
CommentsMain text:20 pages, 4 figures; SI: 20 pages, 9 figures. Comments are welcome
