扭曲半导体中拓扑莫尔带的目录

中文摘要 AI 辅助

扭曲二维半导体为平坦和拓扑莫尔微带提供了一条途径，但组织其材料依赖性的系统原理仍不清楚。在此，我们建立了一个高通量框架，该框架整合了结构弛豫、第一性原理电子结构计算和莫尔带拓扑。我们将此框架应用于43个实验实现的单层和91个对称不等价的双层原型，产生了1000多个角度分辨的莫尔电子能带结构。该数据库表明，低能莫尔电子结构主要由母带边缘的谷特征和堆叠对称性组织。在Γ谷系统中，微带宽度通常遵循近二次扭曲角缩放，与以折叠为主的动能尺度一致。在K谷系统中，堆叠控制的层间杂化决定了母贝里曲率是否重新分布到孤立的谷陈微带中。相比之下，M谷系统形成了一个更具材料特异性的类别，与各向异性和对称约束的能带折叠相关。相同的谷和堆叠层次结构解释了Z2微带的出现或抑制，并且Janus双层中的表面终止提供了一个用于改变相关谷特征的微观旋钮。这些结果为设计扭曲半导体中的平坦和拓扑莫尔带建立了材料级的组织原则。

英文摘要

Twisted two-dimensional semiconductors provide a route to flat and topological moiré minibands, but systematic principles for organizing their material dependence have remained unclear. Here, we establish a high-throughput framework that integrates structural relaxation, first-principles electronic structure calculations, and moiré band topology. We apply this framework to 43 experimentally realized monolayers and 91 symmetry-inequivalent bilayer prototypes, yielding over 1,000 angle-resolved moiré electronic band structures. This database reveals that the low-energy moiré electronic structure is organized primarily by the valley character of the parent band edge together with stacking symmetry. In $Γ$-valley systems, the miniband width usually follows a nearly quadratic twist-angle scaling, consistent with a folding-dominated kinetic-energy scale. In $K$-valley systems, stacking-controlled interlayer hybridization governs whether parent Berry curvature is redistributed into isolated valley Chern minibands. By contrast, $M$-valley systems form a more material-specific class associated with anisotropic and symmetry-constrained band folding. The same valley-and-stacking hierarchy rationalizes the emergence or suppression of $\mathbb{Z}_2$ minibands, and surface termination in Janus bilayers provides a microscopic knob for changing the relevant valley character. These results establish a materials-level organizing principle for designing flat and topological moiré bands in twisted semiconductors.

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7 pages, 3 figures