Graphene nanoribbons (GNRs) have recently been shown by Cao, Zhao, and Louie [Cao, T.; Zhao, F.; Louie, S. G. Phys. Rev. Lett.2017, 119, 076401] to possess distinct topological phases in general, characterized by a ₂ invariant. Cove-edged and chevron GNRs moreover are chemically and structurally diverse, quasi-one-dimensional (1D) nanostructures whose structure and electronic properties can be rationally controlled by bottom-up synthesis from precursor molecules. We derive the value of the topological invariant of the different types of cove-edged and chevron GNRs, and we investigate the electronic properties of various junctions formed by these GNRs, as well as such GNRs with the more common armchair or zigzag GNRs. We study the topological junction states at the interface of two topologically distinct segments. For an isolated GNR having two ends of different terminations, topological end states are shown to develop only at the topologically nontrivial end. Our work extends the explicit categorization of topological invariants of GNRs beyond the previously demonstrated armchair GNRs and provides new design rules for novel GNR junctions as well as future GNR-based nanoelectronic devices.

中文翻译：

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湾边和人字形石墨烯纳米带的拓扑相：几何结构，_2个不变式和结状态

曹，赵和路易（Cao，T .; 赵峰；路易（Louie），SG物理。莱特牧师 2017年，119，076401]到具有一般不同拓扑相，其特征在于由₂不变的 而且，凹形和人字形的GNR在化学和结构上都是准一维（1D）纳米结构，其结构和电子特性可以通过由前体分子进行自下而上的合成来合理控制。我们推导了不同类型的弧形和人字形GNR的拓扑不变性的值，并且我们研究了由这些GNR以及具有更常见的扶手椅形或Z字形GNR的GNR形成的各种结的电子性质。我们研究两个拓扑不同段的接口处的拓扑结状态。对于具有不同末端的两个末端的孤立GNR，拓扑末端状态仅在拓扑非平凡末端显示。