Superconductors with Topological Order

TL;DR

This paper introduces a topological mechanism for superconductivity, where the ground state degeneracy and effective theory differ from traditional symmetry-breaking models, exemplified by Josephson junction arrays.

Contribution

It presents a novel topological approach to superconductivity, moving beyond Landau symmetry-breaking theories, with a concrete realization in Josephson junction arrays.

Findings

Topological ground state degeneracy on non-trivial manifolds

Effective theory based on emerging gauge fields

Realization in Josephson junction arrays

Abstract

We propose a mechanism of superconductivity in which the order of the ground state does not arise from the usual Landau mechanism of spontaneous symmetry breaking but is rather of topological origin. The low-energy effective theory is formulated in terms of emerging gauge fields rather than a local order parameter and the ground state is degenerate on topologically non-trivial manifolds. The simplest example of this mechanism of superconductivty is concretely realized as global superconductivty in Josephson junction arrays.