Probing optical anapoles with fast electron beams
Journal article, 2023
Optical anapoles are intriguing charge-current distributions characterized by a strong suppression of electromagnetic radiation. They originate from the destructive interference of the radiation produced by electric and toroidal multipoles. Although anapoles in dielectric structures have been probed and mapped with a combination of near- and far-field optical techniques, their excitation using fast electron beams has not been explored so far. Here, we theoretically and experimentally analyze the excitation of optical anapoles in tungsten disulfide (WS2) nanodisks using Electron Energy Loss Spectroscopy (EELS) in Scanning Transmission Electron Microscopy (STEM). We observe prominent dips in the electron energy loss spectra and associate them with the excitation of optical anapoles and anapole-exciton hybrids. We are able to map the anapoles excited in the WS2 nanodisks with subnanometer resolution and find that their excitation can be controlled by placing the electron beam at different positions on the nanodisk. Considering current research on the anapole phenomenon, we envision EELS in STEM to become a useful tool for accessing optical anapoles appearing in a variety of dielectric nanoresonators.
Author
Carlos Maciel-Escudero
CIC nanoGUNE
Spanish National Research Council (CSIC)
Andrew Yankovich
Chalmers, Physics, Nano and Biophysics
Battulga Munkhbat
Technical University of Denmark (DTU)
Chalmers, Physics, Nano and Biophysics
Denis Baranov
Chalmers, Physics, Nano and Biophysics
Moscow Institute of Physics and Technology
Rainer Hillenbrand
CIC nanoGUNE
Basque Foundation for Science (Ikerbasque)
Eva Olsson
Chalmers, Physics, Nano and Biophysics
Javier Aizpurua
Spanish National Research Council (CSIC)
Donostia International Physics Center
Timur Shegai
Chalmers, Physics, Nano and Biophysics
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 14 1 8478Kvantplasmonik – en teknologi för foton-fotonväxelverkan på kvantnivå vid rumstemperatur
Swedish Research Council (VR) (2016-06059), 2017-01-01 -- 2022-12-31.
Plasmon-exciton coupling at the attosecond-subnanometer scale: Tailoring strong light-matter interactions at room temperature
Knut and Alice Wallenberg Foundation (2019.0140), 2020-07-01 -- 2025-06-30.
Subject Categories (SSIF 2011)
Computational Mathematics
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Other Physics Topics
Condensed Matter Physics
DOI
10.1038/s41467-023-43813-y
PubMed
38123545