发表机构
Donostia International Physics Center (DIPC); University of the Basque Country (UPV/EHU); Aalto University School of Science; Department of Physics, University of Science and Technology of China; CIC nanoGUNE; Max Planck Institute for Chemical Physics of Solids; Diamond Light Source Ltd（多诺斯蒂亚国际物理中心; 巴斯克大学; 阿尔托大学理学院; 中国科学技术大学物理系; nanoGUNE创新中心; 马克斯·普朗克固体化学物理研究所; 钻石光源有限公司）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过ARPES、DFT和DMFT方法，发现Kagome金属LuFe6Ge6中的瀑布状谱特征源于范霍夫奇点附近的光电子非弹性散射，而非强电子关联，为理解此类谱特征提供了新视角。
AI 中文摘要
由角分辨光电子能谱（ARPES）观察到的瀑布状谱特征通常与强电子关联或电子-玻色子耦合相关。在此，我们利用偏振依赖的ARPES、密度泛函理论和动力学平均场理论，研究了FeGe衍生家族中结构简单的成员——Kagome金属LuFe6Ge6中的这一关联。我们在L点观察到一个显著的垂直谱特征，其束缚能延伸超过数百毫电子伏特。其轨道特征被识别为主要是Fe dyz轨道，其能量起始点与位于费米能级EF以下约0.3 eV处的范霍夫奇点一致。尽管存在瀑布状谱响应，动力学平均场理论（DMFT）仅揭示了弱的电子关联，而计算出的电子结构紧密再现了实验体带。我们提出，这种反常谱权重可能源于出射光电子的非弹性散射，可能与范霍夫奇点附近的大态密度有关。我们的结果表明，瀑布状特征可以在没有强电子关联的情况下出现，并强调了底层能带结构和光电子能量损失过程在其解释中的可能作用。
英文摘要
Waterfall-like spectral features observed by angle-resolved photoemission spectroscopy (ARPES) are commonly associated with strong electronic correlations or electron-boson coupling. Here, we investigate this connection in the kagome metal LuFe6Ge6, a structurally simple member of the FeGe-derived family, using polarization-dependent ARPES, density functional theory and dynamical mean-field theory. We observe a pronounced vertical spectral feature at the L point extending over several hundred meV in binding energy. Its orbital character is identified as predominantly Fe dyz, and its energy onset coincides with a van Hove singularity located approximately 0.3 eV below EF . Despite the waterfall-like spectral response, dynamical mean-field theory (DMFT) reveals only weak electronic correlations, while the calculated electronic structure closely reproduces the experimental bulk bands. We propose that the anomalous spectral weight may arise from inelastic scattering of the outgoing photoelectrons, potentially associated with the large density of states near the van Hove singularity. Our results suggest that waterfall-like features can emerge without strong electronic correlations and highlight the possible role of the underlying band structure and photoelectron energy-loss processes in their interpretation.
