发表机构
Institute of Physics, Czech Academy of Sciences; Université de Strasbourg; CNRS; Georg-August-Universität Göttingen; Donostia International Physics Center; Ikerbasque, Basque Foundation for Science（捷克科学院物理研究所; 斯特拉斯堡大学; 法国国家科学研究中心; 哥廷根大学; 多诺斯蒂亚国际物理中心; 伊克尔巴斯克科学基金会）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究二维分子晶体中由双重简并激发产生的动量锁定边缘激子，其存在依赖于边界晶向并由Zak相位控制，具有椭圆偏振纹理，可支持定向光学耦合与传输。
AI 中文摘要
在分子晶体中，分子激发可以杂化成集体的弗伦克尔激子。在此，我们展示了平面二维分子晶体中的双重简并激发会产生具有非平凡动量分辨拓扑特性以及仅对特定晶面终止出现的边缘态的激子带。利用受沉积在绝缘表面上的锌酞菁分子聚集体启发的模型，我们证明了边缘激子的存在敏感地依赖于边界的晶向，并由体带的Zak相位控制。由此产生的边缘态展现出源于分子激发内部结构的动量锁定椭圆偏振纹理，可能实现定向光学耦合和激发传输。我们的结果为二维分子材料中实现拓扑和偏振纹理激子态开辟了途径。
英文摘要
In molecular crystals, molecular excitations can hybridize into collective Frenkel excitons. Here we show that doubly degenerate excitations in planar two-dimensional molecular crystals generate excitonic bands with nontrivial momentum-resolved topological characteristics and edge states appearing only for selected crystallographic terminations. Using a model inspired by aggregates of zinc phthalocyanine molecules deposited on insulating surfaces, we demonstrate that the existence of edge excitons depends sensitively on the crystallographic orientation of the boundary and is governed by the Zak phase of the underlying bulk bands. The resulting edge states exhibit momentum-locked elliptical polarization textures originating from the internal structure of the molecular excitations, potentially enabling directional optical coupling and excitation transport. Our results establish a route toward topological and polarization-textured excitonic states in two-dimensional molecular materials.
