Multiple surface plasmons on an unbounded quantum plasma half-space

TL;DR

This paper investigates multiple surface plasmon modes on an unbounded quantum plasma half-space using a quantum hydrodynamic model, revealing their dispersion relations and a notable red-shift compared to bounded plasmas.

Contribution

It introduces a novel analysis of surface plasmons on unbounded quantum plasmas, highlighting multiple modes and their dispersion characteristics.

Findings

Multiple non-normal surface modes exist on unbounded quantum plasma half-spaces.

Surface plasmons exhibit a significant red-shift compared to bounded quantum plasmas.

Dispersion relations for these modes are computed using a spectrum function and cutting condition.

Abstract

The propagation of surface plasmons on a quantum plasma half-space in the absence of any external confinement is investigated. By means of Quantum Hydrodynamic Model in the electrostatic limit it is found that the equilibrium density profile is a smooth continuous function which, in the linear regime, supports multiple non-normal surface modes. Defining a spectrum function and using a cutting condition, the dispersion relations of these modes and their relevance for realistic dynamics are computed. It is found that the multiple surface plasmons present a significant red-shift with respect to the case of fully bounded quantum plasmas.