论文标题
Moiré材料中的拓扑不变和域连接
Topological invariant and domain connectivity in moiré materials
论文作者
论文摘要
最近，已经提出了一种Moiré材料，其中由于较大的Moiré调制，在Moiré单元中出现了不同拓扑阶段的多个域。这种Moiré材料的拓扑特性可能与原始的未透明分层材料不同。在本文中，我们研究了如何在具有多个拓扑结构域的Moiré材料中确定拓扑特性。我们在费米级别的Moiré材料的拓扑不变与真实空间中域结构的拓扑之间显示了对应关系。我们还发现了与截断条件的连续变化兼容的散装对应关系，该条件是特定于Moiré材料的。我们通过调整其Moiré的周期性质量项来证明这些对应关系。这些结果提供了一种可行的方法，可以评估Moiré材料的所有占用带的拓扑不变，并有助于拓扑Moiré材料和设备的设计。
Recently, a moiré material has been proposed in which multiple domains of different topological phases appear in the moiré unit cell due to a large moiré modulation. Topological properties of such moiré materials may differ from that of the original untwisted layered material. In this paper, we study how the topological properties are determined in moiré materials with multiple topological domains. We show a correspondence between the topological invariant of moiré materials at the Fermi level and the topology of the domain structure in real space. We also find a bulk-edge correspondence that is compatible with a continuous change of the truncation condition, which is specific to moiré materials. We demonstrate these correspondences in the twisted Bernevig-Hughes-Zhang model by tuning its moiré periodic mass term. These results give a feasible method to evaluate a topological invariant for all occupied bands of a moiré material, and contribute to the design of topological moiré materials and devices.
