Abstract

The high-order harmonic generation in finite topological nanoribbons is investigated using a tight-binding approximation. The narrow, two-dimensional ribbons consist of hexagonal structures. A topological phase transition is defined by a sudden change of the topological invariant. In the bulk, this kind of phase transition might occur if an existing band gap closes and reopens again. Through the bulk-boundary correspondence, this is related to the emergence of topologically protected edge states in the respective finite systems. For the finite ribbons studied in this work, the variation of the tight-binding parameters leads to the emergence of two edge states after the closing of the band gap. The energies of those edge states as functions of the tight-binding parameters display crossings and avoided crossings, which influence the high-harmonic spectra.

Graphic Abstract

中文翻译：

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边缘状态对拓扑纳米带中高次谐波产生的影响

摘要

使用紧束缚近似研究了有限拓扑纳米带中的高次谐波产生。狭窄的二维带由六边形结构组成。拓扑相变由拓扑不变量的突然变化定义。一般来说，如果现有的带隙关闭并重新打开，可能会发生这种相变。通过体边界对应，这与相应有限系统中拓扑保护边缘状态的出现有关。对于这项工作中研究的有限带，紧束缚参数的变化导致在带隙关闭后出现两个边缘状态。这些边缘态的能量作为紧束缚参数的函数显示交叉和避免交叉，

图形摘要