Switching nonlinearity in a superconductor-enhanced metamaterial

TL;DR

This paper presents a superconducting metamaterial capable of switching between high and low transmission states by modulating incident power, leveraging superconductivity quenching in Nb films to achieve significant transmission contrast and delay changes.

Contribution

It introduces a nonlinear metamaterial that uses superconducting Nb films to enable power-controlled switching of electromagnetic transmission.

Findings

Achieved 10 dB transmission contrast

Demonstrated 70 ns change in group delay

Controlled superconducting state with 22 dBm RF power

Abstract

We demonstrate a nonlinear metamaterial that can be switched between low and high transmission by controlling the power level of the incident beam. The origin of this nonlinear response is the superconducting Nb thin film employed in the metamaterial structure. We show that with moderate RF power of about 22 dBm it is possible to quench the superconducting state as a result of extremely strong current densities at the corners of the metamaterial's split-ring resonators. We measure a transmission contrast of 10 dB and a change in group delay of 70 ns between the low and high power states.