Relaxing Graphene Plasmon Excitation Constraints Through the Use of an Epsilon-Near-Zero Substrate

Alvarenga V.T.; Bahamon D.A.; Peres N.M.R.; de Matos C.J.S.

Relaxing Graphene Plasmon Excitation Constraints Through the Use of an Epsilon-Near-Zero Substrate

Tipo

Artigo

Data de publicação

2023

Periódico

Plasmonics

Citações (Scopus)

1

Autores

Alvarenga V.T.
Bahamon D.A.
Peres N.M.R.
de Matos C.J.S.

Resumo

© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Graphene plasmons have attracted significant attention due to their tunability, potentially long propagation lengths and ultracompact wavelengths. However, the latter characteristic imposes challenges to light-plasmon coupling in practical applications, generally requiring sophisticated coupling setups, extremely high doping levels and/or graphene nanostructuring close to the resolution limit of current lithography techniques. Here, we propose and theoretically demonstrate a method for alleviating such a technological strain through the use of a practical substrate whose low and negative dielectric function naturally enlarges the graphene polariton wavelength to more manageable levels. We consider silicon carbide (SiC), as it exhibits a dielectric function whose real part is between - 1 and 0, while its imaginary part remains lower than 0.05, in the 951 to 970 cm- 1 mid-infrared spectral range. Our calculations show hybridization with the substrate’s phonon polariton, resulting in a polariton wavelength that is an order of magnitude longer than obtained with a silicon dioxide substrate, while the propagation length increases by the same amount.