Probing nonlocal effects in metals with graphene plasmons

• Autor(a) principal: Dias, Eduardo J. C.
• Data de Publicação: 2018
• Outros Autores: Iranzo, David Alcaraz, Gonçalves, P. A. D., Hajati, Yaser, Bludov, Yuliy V., Jauho, Antti-Pekka, Mortensen, N. Asger, Koppens, Frank H. L., Peres, N. M. R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/56810
• topic: Graphene; Plasmons; Ciências Naturais::Ciências Físicas; Science & Technology

In this paper we analyze the effects of nonlocality on the optical properties of a system consisting of a thin metallic film separated from a graphene sheet by a hexagonal boron nitride (hBN) layer. We show that nonlocal effects in the metal have a strong impact on the spectrum of the surface plasmon-polaritons on graphene. If the graphene sheet is shaped into a grating, we show that the extinction curves can be used to shed light on the importance of nonlocal effects in metals. Therefore, graphene surface plasmons emerge as a tool for probing nonlocal effects in metallic nanostructures, including thin metallic films. As a byproduct of our study, we show that nonlocal effects lead to smaller losses for the graphene plasmons than what is predicted by a local calculation. We show that these effects can be very well mimicked using a local theory with an effective spacer thickness larger than its actual value.