发表机构
Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau; Hanyang University（莱茵兰-普法尔茨技术大学凯泽斯劳滕-兰道校区; 汉阳大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出广义s-d模型，以CrSBr双层为案例，结合自旋与层赝自旋量子数守恒，揭示层状A型反铁磁半导体的亮暗激子态，为相关研究提供指导。
AI 中文摘要
近期在某些范德瓦尔斯磁性半导体中发现了与磁序耦合的激子，以及随之产生的强磁光响应，这在磁学与半导体光学的交叉领域引发了大量研究活动。本文提出了一个解析上易于处理的最小模型，在统一框架内描述磁序、电子、空穴和激子，从而捕捉广泛的现象。该模型将磁序与巡游载流子视为由不同电子轨道构成，这些轨道通过轨道相关的在位交换相互耦合，类似于金属磁体中s-d模型的处理方式。以CrSBr双层为案例研究，我们将该模型及其预测与近期实验和从头计算结果进行对比，发现二者吻合良好，且该模型的简洁性还带来了新的见解。研究光学选择定则时，我们发现由自旋和层赝自旋组合形成的量子数守恒是一个有用的指导原则，即使在非共线磁构型中也成立。分析表明，这类层状A型反铁磁体中存在一系列亮激子态和暗激子态。本文提出的框架应有助于直观理解近期发现的激子现象，并为层状磁性半导体中其他激子态的发现提供指导。
英文摘要
The recent discovery of excitons coupled to the magnetic order, and the consequent strong magneto-optic responses, in some van der Waals magnetic semiconductors has triggered intense activity at the interface of magnetism and semiconductor optics. Here, we present an analytically tractable minimal model that describes magnetic order, electrons, holes, and excitons within a unified framework, thereby capturing a wide range of phenomena. It treats the magnetic order and itinerant carriers to be comprised by distinct electronic orbitals that are mutually coupled via orbital-dependent onsite exchange, similar to the treatment of metallic magnets using an s-d model. Investigating CrSBr bilayer as a case study, we benchmark our model and its predictions against recent experimental and ab-initio results finding good agreement as well as new insights enabled by the model's simplicity. Examining the optical selection rules, we find the conservation of a quantum number formed from a combination of spin and layer pseudospin to be a useful guiding principle, even in noncollinear magnetic configurations. Our analysis finds a series of bright and dark excitonic states in such layered A-type antiferromagnets. The presented framework should be valuable in achieving intuitive understanding of recently discovered excitonic phenomena and guiding the discovery of other excitonic states in layered magnetic semiconductors.
Comments34 pages, 10 figures
