标题： 拓扑轨道霍尔效应 显示英文标题

标题： Topological Orbital Hall Effect

摘要： 轨道霍尔效应（OHE）因其在基础科学上的意义以及在轨道电子学和自旋电子学中的潜在应用而引起了广泛关注。与自旋霍尔效应不同，OHE与能带拓扑之间的联系尚未被很好地理解。在此，我们提出了一种基于分析投影轨道角动量（POAM）谱的新方法来理解OHE。通过考虑IV族元素的单层结构，我们证明了POAM谱的Wannier电荷中心显示出拓扑非平凡的缠绕。发现轨道霍尔电导率在能隙内形成一个平台，这是由POAM谱携带的Chern数直接导致的。拓扑轨道霍尔相表现出一种新的体-边界对应关系，该关系在POAM谱中具有无能隙态，并在边界上诱导出非零的轨道纹理，这些可以通过ARPES测量进行实验验证。我们的研究提供了一种系统的方法来研究拓扑OHE，并为在二维材料中对其更广泛的探索提供了途径。 显示英文摘要

摘要： The orbital Hall effect (OHE) is attracting recent interest due to its fundamental science implications and potential applications in orbitronics and spintronics. Unlike the spin Hall effect, the connection between the OHE and band topology is not well understood. Here we present a novel approach for understanding the OHE based on analyzing the projected orbital angular momentum (POAM) spectrum. By considering monolayers of group IV elements, we demonstrate that the Wannier charge centers of the POAM spectrum display topologically nontrivial windings. The orbital Hall conductivity is found to form a plateau within the band gap as a direct consequence of the Chern number carried by the POAM spectrum. The topological orbital Hall phase is shown to yield a new form of bulk-boundary correspondence, which features gapless states in the POAM spectrum and induces nonzero orbital textures at the boundaries that should be amenable to experimental verification through ARPES measurements. Our study presents a systematic method for investigating the topological OHE and provides a pathway for its broader exploration in two-dimensional materials.