Landau damping in hybrid plasmonics

TL;DR

This paper investigates how Landau damping in hybrid metal-dielectric nanostructures can be controlled by material properties, revealing that dielectric choice significantly influences plasmon decay and hot carrier generation for optoelectronic applications.

Contribution

It provides a theoretical analysis of Landau damping in hybrid plasmonic structures, highlighting the impact of dielectric permittivity and electron effective mass on decay rates and hot carrier production.

Findings

LD can be enhanced by an order of magnitude with specific dielectric properties.

Electron spillover into the dielectric increases electric field and damping.

Interface transition absorption dominates Landau damping in hybrid structures.

Abstract

Landau Damping (LD) mechanism of the Localized Surface Plasmon (LSP) decay is studied for the hybrid nanoplasmonic (metal core/dielectric shell) structures. It is shown that LD in hybrid structures is strongly affected by permittivity and electron effective mass in the dielectric shell in accordance with previous observations by Kreibig, and the strength of LD can be enhanced by an order of magnitude for some combinations of permittivity and effective mass. The physical reason for this effect is identified as electron spillover into the dielectric where electric field is higher than in the metal and the presence of quasi-discrete energy levels in the dielectric. The theory indicates that the transition absorption at the interface metal-dielectric is a dominant contribution to LD in such hybrid structures. Thus, by judicious selection of dielectric material and its thickness one can engineer decay rates and hot carrier production for important applications, such as photodetection and photochemistry.