Probing the electromagnetic response of dielectric antennas by vortex electron beams

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F23%3APU149138" target="_blank" >RIV/00216305:26620/23:PU149138 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.023192" target="_blank" >https://journals.aps.org/prresearch/abstract/10.1103/PhysRevResearch.5.023192</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevResearch.5.023192" target="_blank" >10.1103/PhysRevResearch.5.023192</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Probing the electromagnetic response of dielectric antennas by vortex electron beams

Popis výsledku v původním jazyce

Focused beams of electrons, which act as both sources and sensors of electric fields, can be used to characterize the electric response of complex photonic systems by locally probing the induced optical near fields. This functionality can be complemented by embracing the recently developed vortex electron beams (VEBs), made up of electrons with orbital angular momentum, which could, in addition, probe induced magnetic near fields. In this work we revisit the theoretical description of this technique, dubbed vortex electron energy-loss spectroscopy (v-EELS). We map the fundamental, quantum-mechanical picture of the scattering of the VEB electrons to the intuitive classical models, which treat the electron beams as a superposition of linear electric and magnetic currents. We then apply this formalism to characterize the optical response of dielectric nanoantennas with v-EELS. Our calculations reveal that VEB electrons probe electric or magnetic modes with different efficiency, which can be adjusted by changing either beam vorticity or acceleration voltage to determine the nature of the probed excitations. We also study a chirally arranged nanostructure, which in the interaction with electron vortices produces dichroism in electron-energy-loss spectra. Our theoretical work establishes VEBs as versatile probes that could provide information on optical excitations otherwise inaccessible with conventional electron beams.

Název v anglickém jazyce

Probing the electromagnetic response of dielectric antennas by vortex electron beams

Popis výsledku anglicky

Focused beams of electrons, which act as both sources and sensors of electric fields, can be used to characterize the electric response of complex photonic systems by locally probing the induced optical near fields. This functionality can be complemented by embracing the recently developed vortex electron beams (VEBs), made up of electrons with orbital angular momentum, which could, in addition, probe induced magnetic near fields. In this work we revisit the theoretical description of this technique, dubbed vortex electron energy-loss spectroscopy (v-EELS). We map the fundamental, quantum-mechanical picture of the scattering of the VEB electrons to the intuitive classical models, which treat the electron beams as a superposition of linear electric and magnetic currents. We then apply this formalism to characterize the optical response of dielectric nanoantennas with v-EELS. Our calculations reveal that VEB electrons probe electric or magnetic modes with different efficiency, which can be adjusted by changing either beam vorticity or acceleration voltage to determine the nature of the probed excitations. We also study a chirally arranged nanostructure, which in the interaction with electron vortices produces dichroism in electron-energy-loss spectra. Our theoretical work establishes VEBs as versatile probes that could provide information on optical excitations otherwise inaccessible with conventional electron beams.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10300 - Physical sciences

Projekt

<a href="/cs/project/GM23-05119M" target="_blank" >GM23-05119M: Tvarované svazky pro novou éru elektronové mikroskopie a spektroskopie</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review Research

ISSN

2643-1564

e-ISSN

—

Svazek periodika

5

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

1-16

Kód UT WoS článku

001048537100004

EID výsledku v databázi Scopus

2-s2.0-85164240140