Thermal self-oscillations in monolayer graphene coupled to a superconducting microwave cavity

TL;DR

This paper reports the observation of thermal self-oscillations in a monolayer graphene coupled to a superconducting microwave cavity, revealing nonlinear thermal effects and enabling evaluation of electron-phonon coupling.

Contribution

It demonstrates thermal self-oscillations in graphene-superconductor systems and models their behavior to assess electron-phonon interactions at low energies.

Findings

Thermal self-oscillations appear as sidebands in cavity transmission.

Oscillations show strong temperature dependence and gate tunability.

Theoretical model based on thermal instability fits experimental data.

Abstract

Nonlinear phenomena in superconducting resonator circuits are of great significance in the field of quantum technology. We observe thermal self-oscillations in a monolayer graphene flake coupled to Molybdenum-Rhenium superconducting resonator. The graphene flake forms a SINIS junction coupled to the resonator with strong temperature dependent resistance. In certain conditions of pump power and frequency, this nonlinearity leads to thermal self-oscillations appearing as sidebands in cavity transmission measurements with strong temperature dependence and gate tunability. The experimental observations fit well with theoretical model based on thermal instability. The modelling of the oscillation sidebands provides a method to evaluate electron phonon coupling in disordered graphene sample at low energies.