Exact solution for square-wave grating covered with graphene: Surface plasmon-polaritons in the THz range

TL;DR

This paper presents an analytical solution for electromagnetic scattering by a square-wave grating with a graphene sheet, revealing strong plasmonic responses and high light absorption in the THz range.

Contribution

It provides the first exact analytical model for surface plasmon-polaritons on graphene-covered gratings, including deep groove and conductivity modulation cases.

Findings

Strong plasmonic response with over 45% light absorption.

Surface plasmon-polaritons are efficiently excited in deep grooves.

Analytical solution enables precise design of graphene-based plasmonic devices.

Abstract

We provide an analytical solution to the problem of scattering of electromagnetic radiation by a square-wave grating with a flat graphene sheet on top. We show that for deep groves there is a strong plasmonic response with light absorption in the graphene sheet reaching more than 45%, due to the excitation of surface plasmon-polaritons. The case of grating with a graphene sheet presenting an induced periodic modulation of the conductivity is also discussed.