Formation of collective excitations in quasi-one dimensional metallic nanostructures: size and density dependance

TL;DR

This paper theoretically studies how collective excitations form in atomic-scale quasi-one-dimensional metallic nanostructures, revealing size and density effects on excitation behavior and differences from three-dimensional systems.

Contribution

It provides a detailed analysis of the transition from quantum to classical excitations and highlights the impact of electron localization due to on-site potentials in nanostructures.

Findings

Transition from quantum to classical plasmon scaling with size and density

Distinct scaling behaviors between quasi-one-dimensional and three-dimensional nanostructures

Electron localization effects due to on-site potential influence response sensitivity

Abstract

We investigate theoretically the formation of collective excitations in atomic scale quasi-one dimensional metallic nanostructures. The response of the system is calculated within the linear response theory and random phase approximation. For uniform nanostructures a transition from quantum single particle excitations to classical plasmon scaling is observed, depending on the system length and electron density. We find crucial differences in the scaling behavior for quasi-one dimensional and three-dimensional nanostructures. The presence of an additional modulating on-site potential is shown to localize electrons, leading to the response function that is highly sensitive to the number of electrons at low fillings.