小角度扭曲双层石墨烯中的完美可控嵌套
Perfect and controllable nesting in the small angle twist bilayer graphene
摘要：
费米面（FS）的平行（“嵌套”）区域驱动电子流体的不稳定性，例如元素铬中的自旋密度波。在一维材料中，FS是平凡地完全嵌套的（一个单一的嵌套向量连接两个“费米点”），而在更高的维度中，只有一小部分FS由平行的薄片组成。我们证明了扭曲双层石墨烯（TBLG）的微小角度制度拥有一个阶段，访问层间偏压，其中FS完全由嵌套的“费米线”：第一个例子完全嵌套FS在二维材料。这种嵌套相被发现在理想以及松弛的扭曲双层结构。我们表现出极好的协议与最近的STM图像的拓扑状态，在这种材料，并阐明这些和基础的费米学之间的联系。我们表明，“费米线”网络的几何形状是可控的所施加的层间偏压的强度，从而TBLG提供了前所未有的访问FS嵌套在2D材料的物理。
英文摘要：
Parallel ("nested") regions of a Fermi surface (FS) drive instabilities of the electron fluid, for example the spin density wave in elemental chromium. In one-dimensional materials, the FS is trivially fully nested (a single nesting vector connects two "Fermi dots"), while in higher dimensions only a fraction of the FS consists of parallel sheets. We demonstrate that the tiny angle regime of twist bilayer graphene (TBLG) possess a phase, accessible by interlayer bias, in which the FS consists entirely of nestable "Fermi lines": the first example of a completely nested FS in a 2d material. This nested phase is found both in the ideal as well as relaxed structure of the twist bilayer. We demonstrate excellent agreement with recent STM images of topological states in this material and elucidate the connection between these and the underlying Fermiology. We show that the geometry of the "Fermi lines" network is controllable by the strength of the applied interlayer bias, and thus that TBLG offers unprecedented access to the physics of FS nesting in 2d materials.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
