A generalized non-local optical response theory for plasmonic nanostructures
A generalized non-local optical response theory for plasmonic nanostructures
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DOI：
10.1038/ncomms4809
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发表时间：
2014-05-01
影响因子：
16.6
通讯作者：
Bozhevolnyi, S. I.
中科院分区：
文献类型：
--
作者：
Mortensen, N. A.;Raza, S.;Bozhevolnyi, S. I.
金属纳米结构表现出与局部表面等离子激元激发相关的大量光学共振。最近对亚纳米到原子尺度等离子体现象的观察刺激了各种复杂理论方法的发展，以描述它们。在这里，我们提出了一个相对简单的半经典广义非局部光学响应理论，它统一了量子压力对流效应和诱导电荷扩散动力学，并伴随有复值广义非局部光学响应参数。我们的理论令人惊讶地很好地解释了单个金属纳米粒子的频移和尺寸相关阻尼，以及观察到的金属纳米粒子二聚体中从键合偶极等离子体到电荷转移等离子体的交叉机制的展宽，从而揭示了一个经典的展宽机制，甚至主导了广泛预期的量子隧道短路。我们预计，我们的理论可以成功地应用于等离子体，广泛的导电介质，包括掺杂半导体和低维材料，如石墨烯。
Metallic nanostructures exhibit a multitude of optical resonances associated with localized surface plasmon excitations. Recent observations of plasmonic phenomena at the sub-nanometre to atomic scale have stimulated the development of various sophisticated theoretical approaches for their description. Here instead we present a comparatively simple semiclassical generalized non-local optical response theory that unifies quantum pressure convection effects and induced charge diffusion kinetics, with a concomitant complex-valued generalized non-local optical response parameter. Our theory explains surprisingly well both the frequency shifts and size-dependent damping in individual metallic nanoparticles as well as the observed broadening of the crossover regime from bonding-dipole plasmons to charge-transfer plasmons in metal nanoparticle dimers, thus unravelling a classical broadening mechanism that even dominates the widely anticipated short circuiting by quantum tunnelling. We anticipate that our theory can be successfully applied in plasmonics to a wide class of conducting media, including doped semiconductors and low-dimensional materials such as graphene.