Uniform plasma oscillations in ellipsoid of conductive material

TL;DR

This paper investigates how the shape of conductive samples, especially ellipsoids, affects the existence and frequency of uniform plasma oscillations, revealing that bulk oscillations are shape-dependent and surface-localized in ellipsoids.

Contribution

It provides a theoretical analysis of plasma oscillations in ellipsoidal conductive samples, deriving frequencies of surface Mie oscillations for arbitrary ellipsoid shapes.

Findings

Bulk dipole oscillations cannot exist in ellipsoids.

Mie oscillations occur on the surface of ellipsoids.

Frequencies of Mie oscillations are calculated for arbitrary ellipsoid shapes.

Abstract

The influence of the shape of a sample on the type of uniform dipole collective electrons oscillations is discussed. In samples of a bulk shape uniform bulk dipole oscillation (Langmuir oscillation) cannot exist. It exists in samples of a thin slab shape only. As uniform bulk dipole oscillations cannot penetrate ellipsoidal samples of conductive material, they exist in the surface layer of a sample only (Mie oscillations). Frequencies of Mie oscillations are alculated for a sample of the shape of an arbitrary ellipsoid.