The approach to a superconductor-to-Bose-insulator transition in disordered films

TL;DR

This paper investigates the superconductor-to-insulator transition in disordered films, revealing two distinct regimes with different scaling behaviors and a universal phase diagram, supporting the dirty boson model.

Contribution

It provides a unified phase diagram for the transition in disordered films and confirms quantum percolation scaling in the strongly disordered regime.

Findings

Resistance at critical point approaches R_Q = h/4e^2

Scaling consistent with quantum percolation

Two distinct disorder regimes identified

Abstract

Through a detailed study of scaling near the magnetic field-tuned superconductor-to-insulator transition in strongly disordered films, we find that results for a variety of materials can be collapsed onto a single phase diagram. The data display two clear branches, one with weak disorder and an intervening metallic phase, the other with strong disorder. Along the strongly disordered branch, the resistance at the critical point approaches $R_Q = h/4e^2$ and the scaling of the resistance is consistent with quantum percolation, and therefore with the predictions of the dirty boson model.