Magnetic monopoles and superinsulation in Josephson junction arrays

TL;DR

This paper demonstrates that magnetic monopole plasma in Josephson junction arrays causes superinsulation through quantum instantons, linking fundamental S-duality concepts to observable phenomena in superconducting systems.

Contribution

It reveals that superinsulation in Josephson junction arrays is caused by quantum instantons forming a magnetic monopole plasma, providing a microscopic mechanism for this phenomenon.

Findings

Magnetic monopole plasma arises as quantum instantons in JJA.

Calculated string tension and minimal system size for superinsulation.

Established connection between S-duality and superinsulation in experiments.

Abstract

Electric-magnetic duality or S-duality, extending the symmetry of Maxwell's equations by including the symmetry between Noether electric charges and topological magnetic monopoles, is one of the most fundamental concepts of modern physics. In two-dimensional systems harboring Cooper pairs, S-duality manifests in the emergence of superinsulation, a state dual to superconductivity, which exhibits an infinite resistance at finite temperatures. The mechanism behind this infinite resistance is the linear charge confinement by a magnetic monopole plasma. This plasma constricts electric field lines connecting the charge-anti-charge pairs into electric strings, in analogy to quarks within hadrons. Yet the origin of the monopole plasma remains an open question. Here we consider a two-dimensional Josephson junction array (JJA) and reveal that the magnetic monopole plasma arises as quantum instantons, thus establishing the underlying mechanism of superinsulation as two-dimensional quantum tunneling events. We calculate the string tension and the dimension of an electric pion determining the minimal size of a system capable of hosting superinsulation. Our findings pave the way for study of fundamental S-duality in desktop experiments on JJA and superconducting films.