Possibility of a zero-temperature metallic phase in granular two-band superconducting films

TL;DR

This paper investigates the potential existence of a zero-temperature metallic phase in two-band granular superconducting films, suggesting it could be observed in certain dirty pnictide superconductors, unlike in single-band films.

Contribution

It introduces a variational approach to study the superconductor-insulator transition in two-band films, revealing a possible metallic phase at zero temperature that is absent in single-band systems.

Findings

Zero-temperature metallic phase may exist in two-band granular superconductors.

Such metallic phase is absent in normal single-band films.

Potential observation in dirty pnictide superconductor films.

Abstract

A variational approach is used to study the superconductor-insulator transition in two-band granular superconducting films using a resistance-shunted Josephson junction array model in this letter. We show that a zero-temperature metallic phase may exist between the superconducting and insulator phases which is absent in normal single band granular superconducting films. The metallic phase may be observable in some dirty pnictide superconductor films.