Superconducting islands, phase fluctuations and the superconductor-insulator transition

TL;DR

This paper discusses how superconducting islands in disordered thin films influence the superconductor-insulator transition, explaining experimental features like non-monotonic magnetoresistance through phase fluctuations and island formation.

Contribution

It introduces a framework based on superconducting islands to explain the superconductor-insulator transition and related experimental observations in disordered thin films.

Findings

Superconducting islands lead to confined correlations in thin films.

Magnetic fields can induce a transition from superconducting to insulating states.

Non-monotonic magnetoresistance is explained by island dynamics.

Abstract

Properties of disordered thin films are discussed based on the viewpoint that superconducting islands are formed in the system. These lead to superconducting correlations confined in space, which are known to form spontaneously in thin films. Application of a perpendicular magnetic field can drive the system from the superconducting state (characterized by phase-rigidity between the sample edges) to an insulating state in which there are no phase-correlations between the edges of the system. On the insulating side the existence of superconducting islands leads to a non-monotonic magnetoresistance. Several other features seen in experiment are explained.