Resonance effects due to the excitation of surface Josephson plasma waves in layered superconductors

Abstract

We analytically examine the excitation of surface Josephson plasma waves (SJPWs) in layered superconductors by an incident electromagnetic wave. The mechanism of excitation is related to the diffraction of the incident wave due to a small periodic modulation in the $\mathbf{a}\mathbf{b}$ plane of the maximum $\mathbf{c}$-axis Josephson current density. We show that the absorption of the incident wave can be substantially increased, for certain incident angles, due to the resonance excitation of SJPWs. The absorption increase is accompanied by a decrease in the specular reflection. Moreover, we find the dependence of the resonance value of the incident angle on the parameters of the superconductor and the frequency of the incident wave, and the depth of the modulations guaranteeing the total absorption (and total suppression of the specular reflection). Numerical examples of the resonance effects are presented for Bi2212 superconductors.