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arXiv · 2209.01471

Topologically localized excitons in single graphene nanoribbons

Song Jiang·Tomas Neuman·Alex Boeglin·Fabrice Scheurer·Guillaume Schull
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Abstract

Excitonic emission from atomically precise graphene nanoribbons (GNRs) synthesised on a metal surface is probed with atomic-scale spatial resolution using a scanning tunneling microscopy (STM) approach. A STM-based strategy to transfer the GNRs to a partially insulating surface is used to prevent light emission quenching of the ribbons by the metal substrate. Sub-nanometer resolved STM-induced fluorescence spectra reveal emission from localized dark excitons build upon the topological end states of the GNRs. A low frequency vibronic emission comb whose characteristics change with the GNR length is attributed to longitudinal acoustic modes confined to a finite box. Overall, our study provides a novel path to investigate the interplay between excitons, vibrons and topology in atomically precise graphene nanostructures.

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Song Jiang, Tomas Neuman, Alex Boeglin, Fabrice Scheurer, Guillaume Schull. 2022-09-03. Topologically localized excitons in single graphene nanoribbons. https://doi.org/10.1126/science.abq6948

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