Visualizing plasmon-exciton polaritons at the nanoscale using electron microscopy
Abstract
Polaritons are compositional light-matter quasiparticles that have recently enabled remarkable breakthroughs in quantum and nonlinear optics, as well as in material science. Despite the enormous progress, however, a direct nanometer-scale visualization of polaritons has remained an open challenge. Here, we demonstrate that plasmon-exciton polaritons, or plexcitons, generated by a hybrid system composed of an individual silver nanoparticle and a few-layer transition metal dichalcogenide can be spectroscopically mapped with nanometer spatial resolution using electron energy loss spectroscopy in a scanning transmission electron microscope. Our experiments reveal important insights about the coupling process, which have not been reported so far. These include nanoscale variation of Rabi splitting and plasmon-exciton detuning, as well as absorption-dominated extinction signals, which in turn provide the ultimate evidence for the plasmon-exciton hybridization in the strong coupling regime. These findings pioneer new possibilities for in-depth studies of polariton-related phenomena with nanometer spatial resolution.
Cite
@article{arxiv.1905.04067,
title = {Visualizing plasmon-exciton polaritons at the nanoscale using electron microscopy},
author = {Andrew B. Yankovich and Battulga Munkhbat and Denis G. Baranov and Jorge Cuadra and Erik Olsén and Hugo Lourenço-Martins and Luiz H. G. Tizei and Mathieu Kociak and Eva Olsson and Timur Shegai},
journal= {arXiv preprint arXiv:1905.04067},
year = {2020}
}