@article{10902/33610,
year = {2020},
month = {5},
url = {https://hdl.handle.net/10902/33610},
abstract = {Atomic vibrations and phonons are an excellent source of information on nanomaterials that we can access through a variety of methods including Raman scattering, infrared spectroscopy, and electron energy-loss spectroscopy (EELS). In the presence of a plasmon local field, vibrations are strongly modified and, in particular, their dipolar strengths are highly enhanced, thus rendering Raman scattering and infrared spectroscopy extremely sensitive techniques. Here, we experimentally demonstrate that the interaction between a relativistic electron and vibrational modes in nanostructures is fundamentally modified in the presence of plasmons. We finely tune the energy of surface plasmons in metallic nanowires in the vicinity of hexagonal boron nitride, making it possible to monitor and disentangle both strong phonon-plasmon coupling and plasmon-driven phonon enhancement at the nanometer scale. Because of the near-field character of the electron beam-phonon interaction, optically inactive phonon modes are also observed. Besides increasing our understanding of phonon physics, our results hold great potential for investigating sensing mechanisms and chemistry in complex nanomaterials down to the molecular level.},
organization = {This project has been funded in part by the European Union through the Horizon 2020 Research and Innovation Program (Grant Agreement 823717), the National Agency for Research under the program of future investment TEMPOS-CHROMATEM (reference no. ANR-10-EQPX-50), the Spanish MINECO (MAT2017-88492-R and SEV2015-0522), the ERC (Advanced Grants 789104-eNANO and 787510- 4DBIOSERS), the Catalan CERCA Program, and Fundació Privada Cellex. The authors would like to thank Javier Aizpurua for helpful comments on strong coupling and Christoph Hanske for help in the nanowire sample preparation. L.H.G.T. would like to thank Andreia Hisi for help during experiments.},
publisher = {American Chemical Society},
publisher = {Nano Letters, 2020, 20(5), 2973-2979},
title = {Tailored nanoscale plasmon-enhanced vibrational electron spectroscopy},
author = {Tizei, Luiz H. G. and Mkhitaryan, Vahagn and Lourenço-Martins, Hugo and Scarabelli, Leonardo and Watanabe, Kenji and Taniguchi, Takashi and Tencé, Marcel and Blazit, Jean-Denis and Li, Xiaoyan and Gloter, Alexandre and Zobelli, Alberto and Schmidt, Franz-Philipp and Liz Marzán, Luis Manuel and García de Abajo, F. Javier and Stéphan, Odile and Kociak, Mathieu},
}