Observation of Stochastic Resonance in Percolative Josephson Media

TL;DR

This paper reports the observation of stochastic resonance in granular superconducting films, where added noise enhances the electrical response to small signals near the percolation threshold.

Contribution

It provides experimental evidence of stochastic resonance in percolative Josephson media, a phenomenon not previously demonstrated in such systems.

Findings

Voltage response increases with added noise

Gain coefficient and SNR show maxima at specific noise levels

Resonance occurs near the percolation threshold

Abstract

Measurements of the electrical response of granular Sn-Ge thin films below the superconducting transition temperature are reported. The addition of an external noise to the magnetic field applied to the sample is found to increase the sample voltage response to a small externally applied ac signal. The gain coefficient for this signal and the signal-to-noise ratio display clear maxima at particular noise levels. We interpret these observations as a stochastic resonance in the percolative Josephson media which occurs close to the percolation threshold.