标题： 手性激子的旋光性 显示英文标题

标题： Optical activity of chiral excitons

摘要： 近年来，手性光学现象领域的研究重点是结构不对称性、电子自旋构型与手性半导体中光物质相互作用之间的联系。 在这些系统中，由于反演对称性破缺和扩展电子态的存在，出现了自旋分裂现象，但与手性光学现象的联系尚不明确。 在此，我们开发了一个手性激子的解析有效质量模型，该模型通过密度泛函理论进行参数化。 该模型考虑了由于极性畸变导致的带边布洛赫函数的宇称混合，从而产生磁偶极允许的跃迁。 通过对一种典型的手性二维杂化钙钛矿半导体的研究，我们表明手性激子及其介带连续体的圆二色性源于自旋分裂，这是通过类似Rashba的自旋纹理和手性/螺旋自旋纹理组分的交叉耦合产生的。 作为对比，我们将该模型应用于描述在没有手性晶格畸变的情况下钙钛矿纳米晶体中激子的手性光学特性。 显示英文摘要

摘要： Recent activity in the area of chiroptical phenomena has been focused on the connection between structural asymmetry, electron spin configuration and light matter interactions in chiral semiconductors. In these systems, spin-splitting phenomena emerge due to inversion symmetry breaking and the presence of extended electronic states, yet the connection to chiroptical phenomena is lacking. Here, we develop an analytical effective mass model of chiral excitons, parameterized by density functional theory. The model accounts for parity mixing of the band edge Bloch functions resulting from polar distortions, resulting in magnetic dipole allowed transitions. Through the study of a prototypical chiral 2D hybrid perovskite semiconductor, we show that circular dichroism of the chiral exciton and its interband continuum emerges from spin-splitting via cross coupling of Rashba-like and chiral/helical spin-texture components. As a counterpoint, we apply our model to describe chiroptical properties of excitons in perovskite nanocrystals that occur without chiral lattice distortions.