标题： 拓扑材料中的缺陷束缚激子 显示英文标题

标题： Defect-Bound Excitons in Topological Materials

摘要： 激子是由电子和空穴组成的束缚态，它们受到材料底层能带结构性质的影响。晶格系统中的缺陷可能捕获电子缺陷态，电子可以被激发到这些态上形成缺陷束缚激子。在这里，我们研究了单一位置缺陷系统中能带拓扑对激子的影响。我们展示了在稳健的拓扑相中，当出现间隙内的环状电子态时，激子会继承这些环状态的特性：由于缺陷态的宽空间分布，激子的结合能降低，并且由于拓扑能带的混合轨道特性，它们的波函数具有复杂的形状和有序性。我们的研究推进了对拓扑在量子材料中修改和控制缺陷束缚激子作用的理解。 显示英文摘要

摘要： Excitons, bound states of electrons and holes, are affected by the properties of the underlying band structure of a material. Defects in lattice systems may trap electronic defect states, to which an electron can be excited to form defect-bound excitons. Here, we examine the effect of band topology on excitons in systems with a single-site defect. We show that in the topological phase, when robust, in-gap, ring-shaped electronic states appear around defects, excitons inherit the properties of these ring states: The excitons' binding energies are lowered as a result of the wide spatial profile of the defect state, and their wave functions have complex shapes and order due to the mixed orbital character of the topological bands. Our study advances the understanding of the role of topology in modifying and controlling defect-bound excitons in quantum materials.