The superconductor-superinsulator transition: S-duality and QCD on the desktop

TL;DR

This paper reveals that the superconductor-insulator transition involves topological charge-vortex interactions, leading to three phases, with the superinsulator being a charge confinement state driven by instantons, independent of material disorder.

Contribution

It introduces a topological gauge theory framework that captures the superconductor-insulator transition and identifies the superinsulator as a confinement phase analogous to QCD.

Findings

Identifies three quantum phases: superconductor, superinsulator, and bosonic topological insulator.

Shows superinsulation arises from charge confinement via electric strings generated by instantons.

Demonstrates the transition is governed by four phenomenological parameters in a topological gauge theory.

Abstract

We show that the nature of quantum phases around the superconductor-insulator transition (SIT) is controlled by charge-vortex topological interactions and does not depend on the details of material parameters and disorder. We find three distinct phases, superconductor, superinsulator and bosonic topological insulator. The superinsulator is a state of matter with infinite resistance in a finite temperature range, which is the S-dual of the superconductor and in which charge transport is prevented by electric strings binding charges of opposite sign. The electric strings ensuring linear confinement of charges are generated by instantons and are dual to superconducting Abrikosov vortices. Material parameters and disorder enter the London penetration depth of the superconductor, the string tension of the superinsulator and the quantum fluctuation parameter driving the transition between them. They are entirely encoded in four phenomenological parameters of a topological gauge theory of the SIT. Finally, we point out that, in the context of strong coupling gauge theories, the many-body localization phenomenon that is often referred to as an underlying mechanism for superinsulation is a mere transcription of the well-known phenomenon of confinement into solid state physics language and is entirely driven by endogenous disorder embodied by instantons with no need of exogenous disorder.