Title: Chirality-Driven Magnetization Emerges from Relativistic Four-Current Dynamics Show Chinese title

Title: 手性驱动的磁化源于相对论四电流动力学

Abstract: Chirality-induced spin selectivity (CISS) is a striking quantum phenomenon in which electron transport through chiral molecules leads to spin polarization -- even in the absence of external magnetic fields or magnetic components. Although observed in systems such as DNA, helicenes, proteins, and polymers, the fundamental physical origin of CISS remains unresolved. Here, we introduce a time-dependent relativistic four-current framework, in which charge and current densities evolve according to the time-dependent variational principle. Real-time relativistic four-current simulations enable direct analysis of helical currents and induced magnetization dynamics. Applied to helicenes -- axially chiral molecules lacking stereocenters -- our simulations reveal curvature-induced helical electron currents that generate spontaneous magnetic fields aligned along the molecular axis. These fields are handedness-dependent and reach magnitudes of $10^{-1}$ Tesla per single helicene strand. Our results suggest that CISS may arise from intrinsic, relativistic curvature-induced helical currents and the associated magnetic fields within chiral molecules. This four-current mechanism offers a self-contained explanation for the driving force underlying spin selectivity, independent of interfacial effects or unphysically enhanced spin--orbit coupling. Furthermore, our results provide a new perspective that offers a unifying framework with the potential to reconcile many existing hypotheses and theoretical models, while also suggesting several testable predictions that can be examined experimentally. Show Chinese abstract

Abstract: 手性诱导自旋选择性（CISS）是一种引人注目的量子现象，其中通过手性分子的电子传输会导致自旋极化——即使在没有外部磁场或磁性组件的情况下也是如此。 尽管在DNA、螺旋烯、蛋白质和聚合物等系统中已经观察到，但CISS的基本物理起源仍未解决。 在此，我们引入了一个时间依赖的相对论四电流框架，在该框架中，电荷和电流密度根据时间依赖变分原理演化。 实时相对论四电流模拟使得可以直接分析螺旋电流和感应磁化动力学。 应用于螺旋烯——轴向手性分子且缺乏立体中心——我们的模拟揭示了由曲率引起的螺旋电子电流，这些电流产生沿分子轴对齐的自发磁场。 这些磁场具有手性依赖性，每条单螺旋烯链的磁场强度可达$10^{-1}$特斯拉。 我们的结果表明，CISS可能源于手性分子内部固有的、相对论性的曲率引起的螺旋电流及其相关的磁场。 这种四电流机制提供了一个自洽的解释，用于解释自旋选择性的驱动力，而不依赖于界面效应或不现实地增强的自旋-轨道耦合。 此外，我们的结果提供了一个新的视角，提供了一个统一的框架，有可能调和许多现有的假设和理论模型，同时提出了几个可实验检验的预测。