Probing the Magnetism of Topological End States in 5-Armchair Graphene Nanoribbons
Probing the Magnetism of Topological End States in 5-Armchair Graphene Nanoribbons
复制标题
DOI：
10.1021/acsnano.9b10191
复制
发表时间：
2020-04-28
期刊：
影响因子：
17.1
通讯作者：
de Oteyza, Dimas G.
中科院分区：
文献类型：
--
作者：
Lawrence, James;Brandimarte, Pedro;de Oteyza, Dimas G.
我们广泛地表征了在Au（111）上合成的具有扶手椅边缘和锯齿形末端的超窄石墨烯纳米带（GNRs）的电子结构，所述超窄石墨烯纳米带在其宽度上具有五个碳原子（5-AGNRs）。在金属衬底和去耦NaCl层上记录的带状物上的扫描隧道光谱测量显示出定义明确的色散带和间隙状态。结合理论计算，我们展示了这些间隙状态是如何拓扑的性质和本地化的锯齿形终端的纳米带。除了合理化的驱动力背后的拓扑类选择的S-AGNRs，我们还发现了长度依赖的行为，这些最终状态从单占据自旋分裂态过渡到一个封闭的壳层的形式，随着带变得更短。最后，我们证明了通过传输实验在一个模型的两端器件结构，其中的色带之间的扫描探针和基板，都作为铅悬浮的最终状态的磁特性。
We extensively characterize the electronic structure of ultranarrow graphene nanoribbons (GNRs) with armchair edges and zigzag termini that have five carbon atoms across their width (5-AGNRs), as synthesized on Au(111). Scanning tunneling spectroscopy measurements on the ribbons, recorded on both the metallic substrate and a decoupling NaCl layer, show well-defined dispersive bands and in-gap states. In combination with theoretical calculations, we show how these in-gap states are topological in nature and localized at the zigzag termini of the nanoribbons. In addition to rationalizing the driving force behind the topological class selection of S-AGNRs, we also uncover the length-dependent behavior of these end states which transition from singly occupied spin-split states to a closed-shell form as the ribbons become shorter. Finally, we demonstrate the magnetic character of the end states via transport experiments in a model two-terminal device structure in which the ribbons are suspended between the scanning probe and the substrate that both act as leads.