Switching the Symmetry of Graphene Plasmons with Nanoemitters for Ultimate Infrared-Light Confinement
Switching the Symmetry of Graphene Plasmons with Nanoemitters for Ultimate Infrared-Light Confinement
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DOI：
10.1103/physrevapplied.19.064039
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发表时间：
2020-12
影响因子：
4.6
通讯作者：
I. Lee;L. Mart'in-Moreno;P. Avouris;T. Low;Sang‐Hyun Oh
中科院分区：
文献类型：
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作者：
I. Lee;L. Mart'in-Moreno;P. Avouris;T. Low;Sang‐Hyun Oh
双层石墨烯中的垂直等离子体耦合导致两种混合等离子体模式：分别在层间间隙中具有对称和反对称电荷分布的光学和声等离子体。然而，在大多数基于远场激发的实验中，双层石墨烯系统中仅主要激发光学等离子体激元。在这里，我们提出了用单个或多个纳米发射器选择性且有效地激发声等离子体激元的策略。这里开发的分析模型阐明了发射器的位置和排列对所得石墨烯等离子体激元对称性的作用。我们提出了一种最佳的设备结构，使得能够对双层石墨烯中的声等离子体进行实验观察，以达到由单原子间隔物定义的等离子体限制的最终水平，这是镜面石墨烯结构无法实现的。
Vertical plasmonic coupling in double-layer graphene leads to two hybridized plasmonic modes: optical and acoustic plasmons with symmetric and anti-symmetric charge distributions across the interlayer gap, respectively. However, in most experiments based on far-field excitation, only the optical plasmons are dominantly excited in the double-layer graphene systems. Here, we propose strategies to selectively and efficiently excite acoustic plasmons with a single or multiple nano-emitters. The analytical model developed here elucidates the role of the position and arrangement of the emitters on the symmetry of the resulting graphene plasmons. We present an optimal device structure to enable experimental observation of acoustic plasmons in double-layer graphene toward the ultimate level of plasmonic confinement defined by a monoatomic spacer, which is inaccesible with a graphene-on-a-mirror architecture.