Singular and Nonsingular Transitions in the Infrared Plasmons of Nearly Touching Nanocube Dimers

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F24%3APU152461" target="_blank" >RIV/00216305:26620/24:PU152461 - isvavai.cz</a>

Result on the web

<a href="https://pubs.acs.org/doi/10.1021/acsnano.4c02644" target="_blank" >https://pubs.acs.org/doi/10.1021/acsnano.4c02644</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acsnano.4c02644" target="_blank" >10.1021/acsnano.4c02644</a>

Result language

angličtina

Original language name

Singular and Nonsingular Transitions in the Infrared Plasmons of Nearly Touching Nanocube Dimers

Original language description

Narrow gaps between plasmon-supporting materials can confine infrared electromagnetic energy at the nanoscale, thus enabling applications in areas such as optical sensing. However, in nanoparticle dimers, the nature of the transition between touching (zero gap) and nearly nontouching (nonzero gap less than or similar to 15 nm) regimes is still a subject of debate. Here, we observe both singular and nonsingular transitions in infrared plasmons confined to dimers of fluorine-doped indium oxide nanocubes when moving from touching to nontouching configurations depending on the dimensionality of the contact region. Through spatially resolved electron energy-loss spectroscopy, we find a continuous spectral evolution of the lowest-order plasmon mode across the transition for finite touching areas, in excellent agreement with the simulations. This behavior challenges the widely accepted idea that a singular transition always emerges in the near-touching regime of plasmonic particle dimers. The apparent contradiction is resolved by theoretically examining different types of gap morphologies, revealing that the presence of a finite touching area renders the transition nonsingular, while one-dimensional and point-like contacts produce a singular behavior in which the lowest-order dipolar mode in the touching configuration, characterized by a net induced charge in each of the particles, becomes unphysical as soon as they are separated. Our results provide valuable insights into the nature of dimer plasmons in highly doped semiconductors.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

<a href="/en/project/GM23-05119M" target="_blank" >GM23-05119M: Shaped beams for a new era of electron microscopy and spectroscopy</a><br>

Continuities

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

Publication year

2024

Confidentiality

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

Name of the periodical

ACS Nano

ISSN

1936-0851

e-ISSN

1936-086X

Volume of the periodical

18

Issue of the periodical within the volume

23

Country of publishing house

US - UNITED STATES

Number of pages

9

Pages from-to

15130-15138

UT code for WoS article

001234463700001

EID of the result in the Scopus database

2-s2.0-85194493735