Impact of graphene on the polarizability of a neighbour nanoparticle: a dyadic Green's function study

TL;DR

This study investigates how graphene, both as a continuous sheet and as a plasmonic grating, significantly enhances and tunes the polarizability of nearby nanoparticles through surface plasmon-polariton excitation, considering retardation effects.

Contribution

It provides a detailed analysis of the renormalized polarizability of nanoparticles near graphene structures, highlighting the effects of surface plasmon-polaritons and geometric tuning.

Findings

Surface plasmon-polaritons in graphene greatly enhance polarizability.

Imaginary part of polarizability can increase by up to 100 times.

Resonance in graphene gratings is narrower and tunable.

Abstract

We discuss the renormalization of the polarizability of a nanoparticle in the presence of either (i) a continuous graphene sheet or (ii) a plasmonic graphene grating, taking into account retardation effects. Our analysis demonstrates that the excitation of surface plasmon-polaritons in graphene produces a large enhancement of the real and imaginary parts of the renormalized polarizability. We show that the imaginary part can be changed by a factor of up to 100 relatively to its value in the absence of graphene. We also show that the resonance in the case of the grating is narrower than in the continuous sheet. In the case of the grating it is shown that the resonance can be tuned by changing the grating geometric parameters.