The superconductor-insulator transition in absence of disorder

TL;DR

This paper derives a microscopic understanding of the superconductor-insulator transition, emphasizing topological effects and phase coexistence without relying on disorder, revealing a complex quantum fluid state.

Contribution

It introduces a disorder-independent, topologically driven framework for the superconductor-insulator transition, highlighting the coexistence of Cooper pairs, vortices, and Wigner crystal phases.

Findings

Disorder and localization are negligible near the critical point.

The ground state is a composite quantum fluid with coexisting phases.

Topological effects govern the phase structure at the transition.

Abstract

We provide a microscopic-level derivation of earlier results showing that, in the critical vicinity of the superconductor-to-insulator transition (SIT), disorder and localization become negligible and the structure of the emergent phases is determined by topological effects arising from the competition between two quantum orders, superconductivity and superinsulation. We find that, around the critical point, the ground state is a composite incompressible quantum fluid of Cooper pairs and vortices coexisting with an intertwined Wigner crystal for the excess (with respect to integer filling) excitations of the two types.