Plasmon-polariton modes in fullerenes

TL;DR

This paper investigates how plasmonic excitations evolve in fullerenes of increasing size, revealing a transition from Mie plasmons to plasmon-polaritons as fullerene size grows, using GW approximation calculations.

Contribution

It provides the first detailed analysis of size-dependent plasmon modes in fullerenes, bridging the understanding between small and large carbon nanostructures.

Findings

High-frequency plasmon-polariton resonance appears in C240.

In C540, plasmon-polariton resonance intensity rivals Mie plasmon.

A gradual transition from Mie plasmons to plasmon-polaritons with increasing size.

Abstract

It is well known that collective electronic excitations in fullerene C$_{60}$ are manifested as Mie plasmons, and in graphene (the limiting case of an infinitely large fullerene) collective excitations are of plasmon-polariton type. How the properties of plasmons change in fullerenes with intermediate sizes is poorly understood. This problem is considered in current paper in the framework of the GW approximation on the example of fullerenes C$_{60}$, C$_{240}$ and C$_{540}$. The calculations show that a high-frequency plasmon-polariton resonance begins to form in C$_{240}$, and in C$_{540}$ the intensity of this resonance becomes comparable to the intensity of Mie plasmon resonance. Thus with a further increase in fullerene size, a gradual transition from Mie plasmons to plasmon-polaritons should be observed.