Probing graphene’s nonlocality with singular metasurfaces

Nanophotonics

article

Emanuele Galiffi¹  Paloma A. Huidobro²  Paulo André D. Gonçalves³  Niels Asger Mortensen³  John B. Pendry¹ 

[1] The Blackett Laboratory, Imperial College London;Instituto de Telecomunicações, Instituto Superior Técnico-University of Lisbon;Center for Nano Optics, University of Southern Denmark, Campusvej 55;Center for Nanostructured Graphene, Technical University of Denmark;Danish Institute for Advanced Study, University of Southern Denmark, Campusvej 55

关键词: graphene plasmonics;    nonlocality;    singular metasurfaces;    singularities;    plasmonics;    local-analogue model;   

DOI  :  10.1515/nanoph-2019-0323

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Singular graphene metasurfaces, conductivity gratings realized by periodically suppressing the local doping level of a graphene sheet, were recently proposed to efficiently harvest THz light and couple it to surface plasmons over broad absorption bands, thereby achieving remarkably high field enhancement. However, the large momentum wavevectors thus attained are sensitive to the nonlocal behavior of the underlying electron liquid. Here, we extend the theory of singular graphene metasurfaces to account for the full nonlocal optical response of graphene and discuss the resulting impact on the plasmon resonance spectrum. Finally, we propose a simple local-analogue model that is able to reproduce the effect of nonlocality in local-response calculations by introducing a constant conductivity offset, which could prove a valuable tool in the modeling of more complex experimental graphene-based platforms.

【 授权许可】

CC BY