AI 中文总结
该研究构造了导带价带拓扑平庸的二维激子模型，证明仅相互作用可产生非平庸陈（Chern）激子，为设计此类拓扑激子建立了通用框架。
AI 中文摘要
激子拓扑通常继承自其基础电子能带的拓扑性质。然而，近期理论研究表明，激子陈数（Chern number）通常可从激子包络波函数的拓扑性质获得额外贡献，这原则上允许即使构成电子带在拓扑上平庸时，也存在相互作用诱导的拓扑激子。在此，我们通过构造一个二维激子模型，提供了该情况的明确实现——该模型的导带和价带在拓扑上平庸，但仍具有通过反转对称性诊断的陈（Chern）激子。从导带和价带的指数局域化Wannier态的实空间极限出发，我们确定了导致涌现激子拓扑的关键要素，并制定了简单的构造方案。我们的工作表明，仅相互作用即可产生非平庸的激子拓扑，且与基础电子带的拓扑无关，同时为设计相互作用诱导的拓扑激子建立了通用框架。
英文摘要
Exciton topology is commonly inherited from the topology of the underlying electronic bands. Recent theoretical work, however, has shown that the exciton Chern number can in general receive an additional contribution from the topology of the exciton envelope wave function, allowing, in principle, interaction-induced topological excitons even when the constituent electronic bands are topologically trivial. Here, we provide an explicit realization of this case by constructing a two-dimensional exciton model with topologically trivial conduction and valence bands that nevertheless hosts a Chern exciton diagnosed by inversion symmetry. Starting from a real-space limit of exponentially localized Wannier states for the conduction and valence bands, we identify the essential ingredients responsible for the emergent exciton topology and formulate a simple construction recipe. Our work demonstrates that interactions alone can generate nontrivial exciton topology, independent of the topology of the underlying electronic bands, and establishes a general framework for designing interaction-induced topological excitons.
Comments6+14 pages, 2+1 figures
