Cooper pairs localization in tree-like networks of superconducting islands

TL;DR

This paper investigates how the topology of tree-like networks of superconducting islands influences the localization of Cooper pairs, revealing the roles of network structure and interactions in their distribution.

Contribution

It introduces a generalized Feynman's approach to analyze Cooper pair localization in complex networks, highlighting the impact of topology and repulsive interactions.

Findings

Cooper pair localization is constrained by network topology.

Repulsive interactions further limit Cooper pair distribution.

Topology-induced confinement affects superconducting properties.

Abstract

We study inhomogeneous Cooper pairs distribution and localization effects in tree-like networks of superconducting islands coupled via Josephson weak links. Using a generalized Feynman's approach, reminiscent of the Bose-Hubbard model, we demonstrate that the Cooper pairs fraction which localizes on a specific network's island is limited by the network topology and, if present, by the repulsive interaction. These findings contribute to clarify the interplay between confinement effects induced by the network's topology and interaction and shed some light on recent experiments dealing with networks of Josephson junctions.