Voltage drop across Josephson junctions for L\'evy noise detection

TL;DR

This paper introduces a method using Josephson junctions to detect and characterize Le9vy noise by measuring voltage drops, even amidst thermal noise, enabling identification of Le9vy fluctuations in complex signals.

Contribution

It presents a novel approach to identify Le9vy-distributed noise via voltage measurements in Josephson junctions, combining analytical and numerical methods for accurate characterization.

Findings

Voltage drop correlates with Le9vy noise intensity.

Method effective at low bias currents and temperatures.

Analytical estimates match numerical simulations.

Abstract

We propose to characterize L\'evy-distributed stochastic fluctuations through the measurement of the average voltage drop across a current-biased Josephson junction. We show that the noise induced switching process in the Josephson washboard potential can be exploited to reveal and characterize L\'evy fluctuations, also if embedded in a thermal noisy background. The measurement of the average voltage drop as a function of the noise intensity allows to infer the value of the stability index that characterizes L\'evy-distributed fluctuations. An analytical estimate of the average velocity in the case of a L\'evy-driven escape process from a metastable state well agrees with the numerical calculation of the average voltage drop across the junction. The best performances are reached at small bias currents and low temperatures, \emph{i.e.}, when both thermally activated and quantum tunneling switching processes can be neglected. The effects discussed in this work pave the way toward an effective and reliable method to characterize L\'evy components eventually present in an unknown noisy signal.