Surface Josephson plasma waves in layered superconductors

TL;DR

This paper predicts the existence of surface Josephson plasma waves in layered superconductors at THz frequencies, which could impact THz detection and optical phenomena.

Contribution

First prediction of propagating surface waves in superconductors, specifically surface Josephson plasma waves in layered superconductors.

Findings

Surface waves exist below the Josephson plasma frequency in layered superconductors.

These waves propagate along the vacuum-superconductor interface and damp outwards.

Potential applications include THz detectors and control of optical reflection phenomena.

Abstract

We predict the existence of surface waves in layered superconductors in the THz frequency range, below the Josephson plasma frequency $\omega_J$. This wave propagates along the vacuum-superconductor interface and dampens in both transverse directions out of the surface (i.e., towards the superconductor and towards the vacuum). This is the first prediction of propagating surface waves in any superconductor. These predicted surface Josephson plasma waves are important for different phenomena, including the complete suppression of the specular reflection from a sample (Wood's anomalies) and a huge enhancement of the wave absorption (which can be used as a THz detector).