Impurity assisted nanoscale localization of plasmonic excitations in graphene

TL;DR

This paper investigates how impurities in graphene induce localized plasmon modes, using a real-space theoretical approach to analyze their properties and tunability, with potential experimental verification via STM.

Contribution

It introduces a real-space method to calculate impurity-induced localized plasmon modes in graphene and explores their tunability through chemical potential and impurity strength.

Findings

Impurities create localized plasmon modes absent in pristine graphene.

Localized modes depend on impurity strength and electronic filling.

Tunable features of localized plasmons can be controlled via chemical potential and impurities.

Abstract

The plasmon modes of pristine and impurity doped graphene are calculated, using a real-space theory which determines the non-local dielectric response within the random phase approximation. A full diagonalization of the polarization operator is performed, allowing the extraction of all its poles. It is demonstrated how impurities induce the formation of localized modes which are absent in pristine graphene. The dependence of the spatial modulations over few lattice sites and frequencies of the localized plasmons on the electronic filling and impurity strength is discussed. Furthermore, it is shown that the chemical potential and impurity strength can be tuned to control target features of the localized modes. These predictions can be tested by scanning tunneling microscopy experiments.