Tamm-Langmuir surface waves

TL;DR

This paper develops a theory for Tamm-Langmuir surface waves in periodic metal-dielectric structures, revealing their unique properties, potential for high sensitivity, and applications in nanophotonics and biosensing.

Contribution

The work introduces the concept of Tamm-Langmuir waves, showing how anisotropy induces photonic band gaps and surface waves with unique dispersion properties.

Findings

Surface waves with singular density of states identified

Anisotropy lifts plasma oscillation degeneracy

Potential for high-sensitivity nanophotonic applications

Abstract

In this work we develop a theory of surface electromagnetic waves localized at the interface of periodic metal-dielectric structures. We have shown that the anisotropy of plasma frequency in metal layers lifts the degeneracy of plasma oscillations and opens a series of photonic band gaps. This results in appearance of surface waves with singular density of states - we refer to them as Tamm-Langmuir waves. Such naming is natural since we have found that their properties are very similar to the properties of both bulk Langmuir and surface Tamm waves. Depending on the anisotropy parameters, Tamm-Langmuir waves can be either forward or backward waves. Singular density of states and high sensitivity of the dispersion to the anisotropy of the structure makes Tamm-Langmuir waves very promising for potential applications in nanophotonics and biosensing.