Zigzag nanoribbons hosting the Haldane Chern insulator model are considered. In this context, a reentrant topological phase, characterized by the emergence of quasi zero dimensional in-gap states, is discussed. The bound states, which reside in the gap opened by the hybridization of the counter-propagating edge modes of the Haldane phase, are localized at the ends of the strip and are found to be robust against on-site disorder. These findings are supported by the behavior of the Zak phase over the parameter space, which exhibits jumps of π in correspondence to the phase transitions between the trivial and the non-trivial phases. The effective mass inversion leading to the jumps in the Zak phase is interpreted in a low energy framework. Setups with non-uniform parameters also show topological bound states via the Jackiw-Rebbi mechanism. All the properties reported are shown to be extremely sensitive to the strip width.

考虑承载 Haldane Chern 绝缘体模型的锯齿形纳米带。在这种情况下，讨论了以准零维带隙态的出现为特征的可重入拓扑相。束缚态位于由霍尔丹相的反向传播边缘模式杂化所打开的间隙中，位于条带的末端，并且被发现对现场无序具有鲁棒性。这些发现得到了 Zak 相在参数空间上的行为的支持，该行为表现出与平凡相和非平凡相之间的相变相对应的π跳跃。导致 Zak 相跳跃的有效质量反转在低能框架中进行解释。具有非均匀参数的设置还通过 Jackiw-Rebbi 机制显示拓扑束缚态。报告的所有特性均显示对带材宽度极为敏感。