Superinsulator as a phase of bi-particle localized states

Abstract

We propose a physical picture of superinsulator observed recently in experiments with superconducting films in a magnetic field. On the basis of previous numerical studies we argue that a moderate attraction creates bi-particle localized states at intermediate disorder strength when noninteracting electron states are delocalized and metallic. Our present numerical study show that such localized pairs are broken by a static electric field which strength is above a certain threshold. We argue that such a breaking of localized pairs by a static field is at the origin of superinsulator breaking with a current jump observed experimentally above a certain critical voltage.