Self-oscillations in a superconducting stripline resonator integrated with a DC-SQUID

TL;DR

This paper investigates self-sustained oscillations in a superconducting stripline resonator with a DC-SQUID, revealing flux-dependent behavior and a thermal instability model, with potential applications in quantum state readout.

Contribution

It introduces a theoretical model linking thermal instability to self-oscillations in a superconducting device, matching experimental observations and suggesting quantum sensing applications.

Findings

Oscillation threshold and frequency are periodic in magnetic flux.

Thermal instability explains the self-oscillations.

Model aligns well with experimental data.

Abstract

We study self-sustained oscillations (SO) in a Nb superconducting stripline resonators (SSR) integrated with a DC superconducting quantum interface devices (SQUID). We find that both the power threshold where these oscillations start and the oscillations frequency are periodic in the applied magnetic flux threading the SQUID loop. A theoretical model which attributes the SO to a thermal instability in the DC-SQUID yields a good agreement with the experimental results. This flux dependant nonlinearity may be used for quantum state reading of a qubit-SSR integrated device.