Ultrafast Plasmonic Response Ensured by Atomic Scale Confinement
Ultrafast Plasmonic Response Ensured by Atomic Scale Confinement
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原子尺度限制确保超快等离子体响应
DOI：
10.1021/acsphotonics.1c01454
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发表时间：
2022
期刊：
影响因子：
7
通讯作者：
M. Kraji
中科院分区：
文献类型：
--
作者：
S. Tanaka;T. Yoshida;K. Watanabe;Y. Matsumoto;T. Yasuike;D. Novko;M. Petrovic;M. Kraji
在过去的十年中，探索等离子体响应中的量子效应引起了越来越多的兴趣。纳米颗粒和颗粒间间隙的极度缩小有望通过金属纳米复合材料上电子波函数的溢出和隧道来改变等离子体共振的性质。虽然过去已经在频域中研究了这种量子效应，但它们在超快时域中的表现仍有待阐明。 在这项工作中，我们通过研究 Cs/石墨烯/Cs/Ir(111) 的新型原子薄多层结构，证明量子效应显着改变超快等离子体响应。原子尺度的限制导致表面等离子体激元的阻尼率降低，从而在几十飞秒内产生强烈的瞬态光学响应。此外，局部激发非热发射复合材料的相干表面声子，在太赫兹频率范围内表现出等离激元带调制。这些新颖的发现将为通过原子级制造定制等离子体诱导过程铺平道路。
Exploring the quantum effects in plasmonic responses has attracted growing interest during the past decade. Extreme downsizing of nanoparticles and interparticle gaps is promising for altering the nature of plasmonic resonances through the spillover and tunneling of electronic wave functions at the metallic nanocomposites. While such quantum effects have been studied in the frequency domain in the past, their manifestation in the ultrafast time domain remains to be elucidated. In this work, we demonstrate that the quantum effect significantly alters the ultrafast plasmonic response by studying a novel atomically thin multilayer structure of Cs/graphene/Cs/Ir(111). The atomic scale confinement leads to a reduction in the damping rate of the surface plasmon–polariton that gives a strong transient optical response within several tens of femtoseconds. In addition, the localized excitation nonthermally launches coherent surface phonons of the composite, exhibiting the plasmon band modulation in the THz frequency range. These novel findings will pave the way for tailoring plasmon-induced processes by the atomic-scale fabrication.