Nonlinear broadening of the plasmon linewidth in a graphene stripe

TL;DR

This paper explains the broad and asymmetric plasmon linewidths observed in graphene by linking them to its linear electron dispersion and the violation of the generalized Kohn theorem, contrasting with semiconductor behaviors.

Contribution

It demonstrates that graphene's linear electron dispersion causes nonlinear broadening of plasmon linewidths, a phenomenon not present in traditional semiconductor structures.

Findings

Graphene exhibits asymmetric and broad plasma resonance linewidths.

The broadening is due to the linear electron energy dispersion.

Violation of the generalized Kohn theorem in graphene explains this behavior.

Abstract

In contrast to semiconductor structures, the experimentally observed plasma resonances in graphene show an asymmetrical and rather broad linewidth. We show that this can be explained by the linear electron energy dispersion in this material and is related to the violation of the generalized Kohn theorem in graphene.