Interdependent Superconducting Networks

TL;DR

This paper presents the first experimental realization of an interdependent superconducting network, demonstrating how Joule heating induces cascades and phase transitions, thus bridging theoretical predictions with physical systems.

Contribution

It introduces a multilayer superconducting system with interdependent layers mediated by Joule heating, experimentally validating interdependent cascade phenomena.

Findings

Joule heating acts as dependency links between layers.

Overheating cascades are triggered by electro-thermal feedback.

Rich phase diagram of resistive transitions and cascades.

Abstract

Cascades are self-amplifying processes triggered by feedback mechanisms that may cause a substantial part of a macroscopic system to change its phase in response of a relatively small local event. The theoretical background for these phenomena is rich and interdisciplinary with interdependent networks providing a versatile "two-interactions" framework to study their multiscale evolution. Yet, physics experiments aimed at validating this ever-growing volume of predictions have remained elusive, hitherto hindered by the problem of identifying possible physical mechanisms realizing interdependent couplings. Here we develop and study the first experimental realization of an interdependent system as a multilayer network of two disordered superconductors separated by an insulating film. We show that Joule heating effects emerging at sufficiently large driving currents act as dependency links between the superconducting layers, igniting overheating cascades via adaptive back and forth electro-thermal feedbacks. Through theory and experiments, we unveil a rich phase diagram of mutual resistive transitions and cascading processes that physically realize and generalize interdependent percolation. The present work establishes the first physics laboratory bench for the manifestation of the theory of interdependent systems, enabling experimental studies to control and to further develop the multilayer phenomena of complex interdependent materials.