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arXiv · 2010.13349

Stochastic resonance in thermally bistable Josephson weak-links and micro-SQUIDs

Sagar Paul·Ganesh Kotagiri·Rini Ganguly·Hervè Courtois·Clemens B. Winkelmann·Anjan K. Gupta
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Abstract

Constriction-based Josephson weak-links display a thermal bi-stability between two states exhibiting zero and finite voltages. This manifests in experiments either as hysteresis in weak-links current voltage characteristics or as random telegraphic signal in voltage. In the latter case, a noise-driven amplification of a sinusoidal excitation of the device is observed, at frequencies matching the characteristic switching frequency in telegraphic signal, a phenomenon known as stochastic resonance. The observed behavior is understood using a two-state model of stochastic resonance and is exploited to illustrate an enhanced signal-to-noise-ratio in a micro-SQUID as a magnetic field sensor.

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Sagar Paul, Ganesh Kotagiri, Rini Ganguly, Hervè Courtois, Clemens B. Winkelmann, Anjan K. Gupta. 2020-10-26. Stochastic resonance in thermally bistable Josephson weak-links and micro-SQUIDs. https://doi.org/10.1103/physrevapplied.15.024009

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