Longitudinal quantum plasmons in copper, gold, and silver

TL;DR

This paper investigates longitudinal quantum plasmons in copper, gold, and silver using a new nonlocal quantum dielectric model, revealing silver's suitability for quantum optical applications due to its low loss.

Contribution

It introduces a novel model for nonlocal quantum dielectric permittivity to analyze quantum plasmons in key metals, advancing understanding of their dispersion and damping properties.

Findings

Silver exhibits the lowest damping rate among the metals studied.

The epsilon near zero properties are characterized for each metal.

Longitudinal quantum plasmons are effectively described in the high photon energy regime.

Abstract

The propagation of plasmonic waves in various metallic quantum nanostructures have considered attention for their applications in technology. The quantum plasmonic properties of metallic nanostructures in the quantum size regime have been difficult to describe by an appropriate model. Here the nonlocal quantum plasmons are investigated in the most important metals of copper, gold, and silver. Dispersion properties of these metals and propagation of longitudinal quantum plasmons in the high photon energy regime are studied by a new model of nonlocal quantum dielectric permittivity. The epsilon near zero properties are investigated and the spectrum and the damping rate of the longitudinal quantum plasmons are obtained in these metals. The quantum plasmon s wave function is shown for both classical and quantum limits. It is shown that silver is the most appropriate for quantum metallic structures in the development of next generation of quantum optical and sensing technologies, due to low intrinsic loss.