Self-induced THz-waves transmissivity of waveguides with finite-length layered superconductors

TL;DR

This paper theoretically predicts a nonlinear electromagnetic phenomenon in layered superconductors within waveguides, where the transmittance can be controlled by wave amplitude, showing hysteresis and potential for self-induced transparency near cutoff frequencies.

Contribution

It introduces a new nonlinear effect in layered superconductors in waveguides, demonstrating controllable transmittance and hysteretic behavior based on incident wave amplitude.

Findings

Transmittance varies from nearly zero to one with amplitude changes.

Hysteretic behavior with jumps in transmittance occurs.

Self-induced transparency can occur at small amplitudes near cutoff frequency.

Abstract

We predict and study theoretically a new nonlinear electromagnetic phenomenon in a sample of layered superconductor of finite length placed in a waveguide with ideal walls. Two geometries are considered here: when the superconducting layers are parallel or perpendicular to the waveguide axis. We show that the transmittance of the superconductor slab can vary over a wide range, from nearly zero to one, when changing the amplitude of the incident wave. Thus, one can induce the total transmission or reflection of the incident wave by just changing its amplitude. Moreover, the dependence of the superconductor transmittance on the incident wave amplitude has a hysteretic behavior with jumps. The considered phenomenon of self-induced transparency can be observed even at small amplitudes, if the wave frequency $\omega$ is close to the cutoff frequency for linear Josephson plasma waves.