Order parameter focalization and critical temperature enhancement in synthetic networks of superconducting islands

Abstract

A generalization of the de Gennes-Alexander micronetworks theory is presented. In this framework, the phase transition of synthetic networks of superconducting islands is described by means of a Ginzburg-Landau approach adapted to the case of granular systems. The general implications of the theory are carefully explained. As a specific example, we demonstrate that star networks support the exponential localization of the order parameter accompanied by an enhancement of the critical temperature of the system. These findings contribute to clarify the physics of the phase transitions in synthetic networks of Josephson-coupled superconducting islands.

Keywords: Ginzburg–Landau theory; de Gennes–Alexander micronetworks theory; phase transitions on a graph.