Plasmons driven by single electrons in graphene nanoislands

Nanophotonics

article

Alejandro Manjavacas¹  Sukosin Thongrattanasiri¹  F. Javier García de Abajo¹ 

[1] IQFR – CSIC

关键词: graphene;    plasmons;    nanophotonics;    graphene plasmonics;    quantum plasmonics;   

DOI  :  10.1515/nanoph-2012-0035

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Plasmons produce large confinement and enhancement of light that enable applications as varied as cancer therapy and catalysis. Adding to these appealing properties, graphene has emerged as a robust, electrically tunable material exhibiting plasmons that strongly depend on the density of doping charges. Here we show that adding a single electron to a graphene nanoisland consisting of hundreds or thousands of atoms switches on infrared plasmons that were previously absent from the uncharged structure. Remarkably, the addition of each further electron produces a dramatic frequency shift. Plasmons in these islands are shown to be tunable down to near infrared wavelengths. These phenomena are highly sensitive to carbon edges. Specifically, armchair nanotriangles display sharp plasmons that are associated with intense near-field enhancement, as well as absorption cross-sections exceeding the geometrical area occupied by the graphene. In contrast, zigzag triangles do not support these plasmons. Our conclusions rely on realistic quantum-mechanical calculations, which are in ostensible disagreement with classical electromagnetic simulations, thus revealing the quantum nature of the plasmons. This study shows a high sensitivity of graphene nanoislands to elementary charges, therefore emphasizing their great potential for novel nano-optoelectronics applications.

【 授权许可】

CC BY