发表机构
Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过畸变kagome紧束缚模型揭示几何变形如何重构平带色散和拓扑，产生量子化Chern数转移及Z2拓扑，为kagome系统平带与拓扑重构提供微观起源解释。
AI 中文摘要
平带形成和非平庸拓扑是kagome电子结构的核心表现，然而它们通常在理想化的晶格几何中被讨论。在畸变kagome材料中，结构变形重组了电子传播路径，但对于这种畸变如何控制平带色散和能带拓扑的微观理解仍然缺乏。利用一个包含旋转角依赖长程跳跃和本征自旋-轨道耦合的畸变kagome紧束缚模型，我们展示了畸变重构了kagome能带流形的色散和拓扑。平带后裔发展出不同的带宽区域，与其在动量空间中极值的重新分布相关。同时，对称相关的能带反转产生量子化的Chern数转移，其奇偶性由接触点的多重性固定，从而决定了间隙分辨的Z2拓扑。伴随的Berry曲率演化产生了特征性的反常霍尔和Nernst响应。这些结果将几何变形确定为kagome系统中平带和拓扑重构的常见微观起源。
英文摘要
Flat band formation and nontrivial topology are central manifestations of kagome electronic structure, yet they are commonly discussed in idealized lattice geometries. In distorted kagome materials, structural deformation reorganizes electronic propagation pathways, but a microscopic understanding of how such distortions govern flat band dispersion and band topology is still lacking. Using a distorted kagome tight-binding model with rotated angle dependent long-range hopping and intrinsic spin-orbit coupling, we show that distortion reconstructs both the dispersion and topology of the kagome band manifold. The flat band descendant develops distinct bandwidth regimes associated with a redistribution of its extrema in momentum space. Simultaneously, symmetry-related band inversions generate quantized Chern number transfer whose parity is fixed by the multiplicity of the touching points, thereby determining the gap-resolved Z2 topology. The accompanying Berry curvature evolution produces characteristic anomalous Hall and Nernst responses. These results identify geometric deformation as a common microscopic origin of flat band and topological reconstruction in kagome systems.
