Thermal Instability and Self-Sustained Modulation in Superconducting NbN Stripline Resonators

TL;DR

This paper investigates the thermal instability leading to self-sustained modulation in superconducting NbN stripline resonators, combining theoretical modeling with experimental validation to reveal a novel nonlinear phenomenon.

Contribution

It introduces a theoretical model explaining self-sustained modulation as a thermal instability, supported by experimental evidence in superconducting NbN resonators.

Findings

Identification of a parameter range for self-sustained modulation

Good agreement between theory and experiment

Demonstration of thermal instability as the underlying mechanism

Abstract

We study theoretically and experimentally the response of a microwave superconducting stripline resonator, integrated with a microbridge, to a monochromatic injected signal. We find that there is a certain range of driving parameters, in which a novel nonlinear phenomenon immerges, and self-sustained modulation of the reflected power off the resonator is generated by the resonator. A theoretical model which attributes the self modulation to a thermal instability yields a good agreement with the experimental results.