Acoustic Mode Hybridization in a Single Dimer of Gold Nanoparticles

Fuente: arXiv
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Main Authors: Girard, Adrien, Gehan, Hélène, Mermet, Alain, Lermé, Jean, Berthelot, Alice, Cottancin, Emmanuel, Crut, Aurelien, Margueritat, Jeremie, Bonnet, Christophe
Format: Preprint
Published: 2024
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_version_ 1866910298320928768
author Girard, Adrien
Gehan, Hélène
Mermet, Alain
Lermé, Jean
Berthelot, Alice
Cottancin, Emmanuel
Crut, Aurelien
Margueritat, Jeremie
Bonnet, Christophe
author_facet Girard, Adrien
Gehan, Hélène
Mermet, Alain
Lermé, Jean
Berthelot, Alice
Cottancin, Emmanuel
Crut, Aurelien
Margueritat, Jeremie
Bonnet, Christophe
contents The acoustic vibrations of single monomers and dimers of gold nanoparticles were investigated by measuring for the first time their ultra-low frequency micro-Raman scattering. This experiment provides access not only to the frequency of the detected vibrational modes, but also to their damping rate, which is obscured by inhomogeneous effects in measurements on ensembles of nano-objects. This allows a detailed analysis of the mechanical coupling occurring between two close nanoparticles (mediated by the polymer surrounding them) in the dimer case. Such coupling induces the hybridization of the vibrational modes of each nanoparticle, leading to the appearance in the Raman spectra of two ultra-low frequency modes corresponding to the out-of-phase longitudinal and transverse (with respect to the dimer axis) quasi-translations of the nanoparticles. Additionally, it is also shown to shift the frequency of the quadrupolar modes of the nanoparticles. Experimental results are interpreted using finite-element simulations, which enable the unambiguous identification of the detected modes and, despite the simplifications made, lead to a reasonable reproduction of their measured frequencies and quality factors. The demonstrated feasibility of low frequency Raman scattering experiments on single nano-objects opens up new possibilities to improve the understanding of nanoscale vibrations, this technique being complementary with single nano-object time-resolved spectroscopy as it gives access to different vibrational modes.
format Preprint
id arxiv_https___arxiv_org_abs_2401_07686
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Acoustic Mode Hybridization in a Single Dimer of Gold Nanoparticles
Girard, Adrien
Gehan, Hélène
Mermet, Alain
Lermé, Jean
Berthelot, Alice
Cottancin, Emmanuel
Crut, Aurelien
Margueritat, Jeremie
Bonnet, Christophe
Optics
The acoustic vibrations of single monomers and dimers of gold nanoparticles were investigated by measuring for the first time their ultra-low frequency micro-Raman scattering. This experiment provides access not only to the frequency of the detected vibrational modes, but also to their damping rate, which is obscured by inhomogeneous effects in measurements on ensembles of nano-objects. This allows a detailed analysis of the mechanical coupling occurring between two close nanoparticles (mediated by the polymer surrounding them) in the dimer case. Such coupling induces the hybridization of the vibrational modes of each nanoparticle, leading to the appearance in the Raman spectra of two ultra-low frequency modes corresponding to the out-of-phase longitudinal and transverse (with respect to the dimer axis) quasi-translations of the nanoparticles. Additionally, it is also shown to shift the frequency of the quadrupolar modes of the nanoparticles. Experimental results are interpreted using finite-element simulations, which enable the unambiguous identification of the detected modes and, despite the simplifications made, lead to a reasonable reproduction of their measured frequencies and quality factors. The demonstrated feasibility of low frequency Raman scattering experiments on single nano-objects opens up new possibilities to improve the understanding of nanoscale vibrations, this technique being complementary with single nano-object time-resolved spectroscopy as it gives access to different vibrational modes.
title Acoustic Mode Hybridization in a Single Dimer of Gold Nanoparticles
topic Optics
url https://arxiv.org/abs/2401.07686