Disentangling bright and dark plasmonic modes in hexagonal nanoprism oligomers

IF 3.5 3区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Photonics and Nanostructures-Fundamentals and Applications Pub Date : 2026-04-01 Epub Date: 2026-04-10 DOI:10.1016/j.photonics.2026.101545

Elham A. Aldufeery

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引用次数: 0

Abstract

We numerically investigate the plasmonic properties of hexagonal oligomers comprising six tip-to-tip triangular nanoprisms, comparing silver (Ag) and gold (Au) structures. By varying the interparticle gap (

G

) from 0 to 100 nm, we used far-field and near-field EELS spectroscopy to map the system’s bright and dark plasmonic modes. We identified a low-energy, “bright” bonding mode that is exceptionally gap-tunable, red-shifting over 1500 nm as

G

approaches 0 nm. Conversely, EELS revealed a high-symmetry “dark” mode that is gap-insensitive in the strong coupling regime, remaining “locked” at

\approx 2.49 eV

(Ag) and

\approx 2.11 eV

(Au). This dichotomy between the highly tunable bright mode and the stable dark mode results in a Fano resonance. Our study clarifies the complementary nature of far- and near-field probes and demonstrates a platform featuring both highly tunable and stable resonances.

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六方纳米棱镜低聚体中亮、暗等离子体模式的解纠缠

我们数值研究了由六个尖端对尖端三角形纳米棱镜组成的六方低聚物的等离子体性质，比较了银（Ag）和金（Au）的结构。通过改变粒子间间隙(G)从0到100 nm，我们使用远场和近场EELS光谱来绘制系统的亮和暗等离子体模式。我们发现了一种低能量，“明亮”的键合模式，它是异常可调的，当G接近0 nm时，红移超过1500 nm。相反，EELS显示出高对称性的“暗”模式，在强耦合区对间隙不敏感，保持在≈2.49eV （Ag）和≈2.11eV （Au）的“锁定”状态。这种高度可调的亮模式和稳定的暗模式之间的二分法导致了范诺共振。我们的研究阐明了远场和近场探测器的互补性，并展示了一个具有高度可调和稳定共振的平台。

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来源期刊

Photonics and Nanostructures-Fundamentals and Applications 工程技术-材料科学：综合

CiteScore

5.00

自引率

3.70%

发文量

审稿时长

62 days

期刊介绍： This journal establishes a dedicated channel for physicists, material scientists, chemists, engineers and computer scientists who are interested in photonics and nanostructures, and especially in research related to photonic crystals, photonic band gaps and metamaterials. The Journal sheds light on the latest developments in this growing field of science that will see the emergence of faster telecommunications and ultimately computers that use light instead of electrons to connect components.