AI 中文总结
研究供体-手性桥-受体分子中手性诱导自旋选择性的微观机制，开发量子动力学模型并引入几何自旋轨道耦合机制，计算结果与实验匹配，为手性自旋电子器件设计提供理论指导。
AI 中文摘要
手性诱导自旋选择性（CISS）已在光激发的供体-手性桥-受体（D-Bχ-A）分子中通过实验观察到[《科学》382, 197 - 201 (2023)]。然而，这种手性体系中CISS的微观机制仍不清楚。本文开发了一个量子动力学模型，精确映射孤立D-Bχ-A分子中联萘型桥二聚体的原子结构，并引入几何自旋轨道耦合（SOC）机制来揭示轴向手性体系中CISS的内在起源。在光激发电子沿扭曲路径传输过程中，几何SOC耦合强度比轻原子的固有耦合强度高1 - 2个数量级，容易产生可观测的高自旋极化。产生的自旋极化包括两个分量：沿手性轴及其垂直方向的与CISS相关的极化是轴向手性固有的，无需外部场或自旋超交换转移，而非阿贝尔曲率校正为手性轴方向提供了严格的数学定义。我们计算的极化分量、手性依赖性和相对大小（30 - 40%）与时间分辨电子顺磁共振测量结果定量匹配。这个几何SOC框架为轴向手性分子中的CISS提供了自洽且通用的物理图景，并为手性自旋电子器件的设计提供了明确的理论指导。
英文摘要
Chiral-induced spin selectivity (CISS) has been experimentally observed in photo-excited donor-chiral bridge-acceptor (D-Bχ-A) molecules [Science 382, 197-201 (2023)]. However, the microscopic mechanism underlying CISS in such chiral systems remains elusive. Here we develop a quantum dynamical model that precisely maps the atomic structure of binaphthyl-type bridge dimers in isolated D-Bχ-A molecules and introduce a geometric spin-orbit coupling (SOC) mechanism to unveil the intrinsic origin of CISS in axially chiral systems. During photo-excited electron transport along the twisted pathways, the geometric SOC coupling strength exceeds the intrinsic coupling of light atoms by one to two orders of magnitude, readily producing observable high spin polarizations. The resulting spin polarization comprises two components: the CISS-associated polarizations along and perpendicular to the chiral axis are intrinsic to axial chirality, requiring neither external fields nor spin-superexchange transfer, while a non-Abelian curvature correction provides a rigorous mathematical definition of the chiral axis direction. Our calculated polarization components, chirality dependence, and relative magnitudes (30-40\%) quantitatively match time-resolved electron paramagnetic resonance measurements. This geometric SOC framework offers a self-consistent and general physical picture of CISS in axially chiral molecules and provides explicit theoretical guidance for the design of chiral spintronic devices.
Comments10 pages, 4 figures
