Landau damping of surface plasmons in metal nanostructures

TL;DR

This paper presents a quantum-mechanical model for Landau damping of surface plasmons in larger metal nanostructures, emphasizing the role of electron surface scattering and its dependence on geometry and field polarization.

Contribution

It introduces a new quantum-mechanical approach to incorporate electron surface scattering into the dielectric function for nanostructures larger than nonlocal effects.

Findings

Surface scattering rate depends on local field polarization.

Analytical results derived for common nanostructure shapes.

Surface scattering significantly influences plasmon decay in nanostructures.

Abstract

We develop a quantum-mechanical theory for Landau damping of surface plasmons in metal nanostructures larger that the characteristic length for nonlocal effects. We show that the electron surface scattering, which facilitates plasmon decay in small nanostructures, can be incorporated into the metal dielectric function on par with phonon and impurity scattering. The derived surface scattering rate is determined by the plasmon local field polarization relative to the metal-dielectric interface and is highly sensitive to the system geometry. We illustrate our model by providing analytical results for surface scattering rate in some common shape nanostructures.