Kinetic theory of surface plasmon polariton in semiconductor nanowires

TL;DR

This paper develops a microscopic kinetic theory using nonequilibrium Green functions to analyze how electron scattering affects surface plasmon polariton damping in semiconductor nanowires, revealing size and temperature dependencies.

Contribution

It introduces a detailed kinetic model that incorporates various electron scattering mechanisms to explain plasmon damping behavior in semiconductor nanowires.

Findings

Electron scattering broadens and shifts plasmon resonance.

Scattering suppresses size-dependent oscillations and temperature effects.

Electron-phonon scattering dominates broadening in InAs nanowires.

Abstract

Based on the semiclassical model Hamiltonian of the surface plasmon polariton and the nonequilibrium Green-function approach, we present a microscopic kinetic theory to study the influence of the electron scattering on the dynamics of the surface plasmon polariton in semiconductor nanowires. The damping of the surface plasmon polariton originates from the resonant absorption by the electrons (Landau damping), and the corresponding damping exhibits size-dependent oscillations and distinct temperature dependence without any scattering. The scattering influences the damping by introducing a broadening and a shifting to the resonance. To demonstrate this, we investigate the damping of the surface plasmon polariton in InAs nanowires in the presence of the electron-impurity, electron-phonon and electron-electron Coulomb scatterings. The main effect of the electron-impurity and electron-phonon scatterings is to introduce a broadening, whereas the electron-electron Coulomb scattering can not only cause a broadening, but also introduce a shifting to the resonance. For InAs nanowires under investigation, the broadening due to the electron-phonon scattering dominates. As a result, the scattering has a pronounced influence on the damping of the surface plasmon polariton: The size-dependent oscillations are smeared out and the temperature dependence is also suppressed in the presence of the scattering. These results demonstrate the the important role of the scattering on the surface plasmon polariton damping in semiconductor nanowires.