论文标题
密闭单层的双向扭曲：在石墨烯及其结晶基板之间的范德华缝隙内的方向排序
Two-way twisting of a confined monolayer: orientational ordering within the van der Waals gap between graphene and its crystalline substrate
论文作者
论文摘要
晶格的二维限制会产生各种秩序和混乱现象。当狭窄的壁具有原子粒度时，预计独特的结构相对于纳米脱水，多孔材料或互化化合物的相关性，其中\ textIt {e.g。}电子状态可以相应地出现。层间的订单对两个限制表面进行的竞争互动感到沮丧。我们重新审视了Novaco和McTague引入的定向订购的概念，以描述晶体表面上不相称的单层的扭曲。随着单层的密度增加，我们预测单层的双向扭曲。我们使用扫描隧道显微镜和电子衍射中发现了存在限制在石墨烯和虹膜表面之间的碱原子单层（钠）中的这种行为。
Two-dimensional confinement of lattices produces a variety of order and disorder phenomena. When the confining walls have atomic granularity, unique structural phases are expected, of relevance in nanotribology, porous materials or intercalation compounds where \textit{e.g.} electronic states can emerge accordingly. The interlayer's own order is frustrated by the competing interactions exerted by the two confining surfaces. We revisit the concept of orientational ordering, introduced by Novaco and McTague to describe the twist of incommensurate monolayers on crystalline surfaces. We predict a two-way twist of the monolayer as its density increases. We discover such a behavior in alkali atom monolayers (sodium, cesium) confined between graphene and an iridium surface, using scanning tunneling microscopy and electron diffraction.
