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arXiv · 2304.08794

Topologically enhanced nonlinear optical response of graphene nanoribbon heterojunctions

Hanying Deng·Zhihao Qu·Yingji He·Changming Huang·Nicolae C. Panoiu·Fangwei Ye
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Abstract

We study the nonlinear optical properties of heterojunctions made of graphene nanoribbons (GNRs) consisting of two segments with either the same or different topological properties. By utilizing a quantum mechanical approach that incorporates distant-neighbor interactions, we demonstrate that the presence of topological interface states significantly enhances the second- and third-order nonlinear optical response of GNR heterojunctions that are created by merging two topologically inequivalent GNRs. Specifically, GNR heterojunctions with topological interface states display third-order harmonic hyperpolarizabilities that are more than two orders of magnitude larger than those of their similarly sized counterparts without topological interface states, whereas the secondorder harmonic hyperpolarizabilities exhibit a more than ten-fold contrast between heterojunctions with and without topological interface states. Additionally, we find that the topological state at the interface between two topologically distinct GNRs can induce a noticeable red-shift of the quantum plasmon frequency of the heterojunctions. Our results reveal a general and profound connection between the existence of topological states and an enhanced nonlinear optical response of graphene nanostructures and possible other photonic systems.

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Hanying Deng, Zhihao Qu, Yingji He, Changming Huang, Nicolae C. Panoiu, Fangwei Ye. 2023-04-18. Topologically enhanced nonlinear optical response of graphene nanoribbon heterojunctions. https://arxiv.org/abs/2304.08794

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