The Chern-Simons term in a dual Josephson junction

TL;DR

This paper explores how introducing fermions into a dual Josephson junction model induces a Chern-Simons term, affecting charge confinement and magnetic instanton behavior in a layered gauge field system.

Contribution

It demonstrates that fermionic quantum fluctuations in a dual Josephson junction induce a Chern-Simons term, altering confinement properties and magnetic instanton dynamics.

Findings

Fermions localize within the (2+1)-D layer due to the dual Meissner effect.

Induced Chern-Simons term destroys electric charge confinement.

Magnetic instantons become confined due to the Chern-Simons term.

Abstract

A dual Josephson junction corresponding to a (2+1)-dimensional non-superconducting layer sandwiched between two (3+1)-dimensional dual superconducting regions constitutes a model of localization of a U(1) gauge field within the layer. Monopole tunneling currents flow from one dual superconducting region to another due to a phase difference between the wave functions of the monopole condensate below and above the non-superconducting layer when there is an electromagnetic field within the layer. These magnetic currents appear within the (2+1)-dimensional layer as a gas of magnetic instanton events and a weak electric charge confinement is expected to take place at very long distances within the layer. In the present work, we consider what happens when one introduces fermions in this physical scenario. Due to the dual Meissner effect featured in the dual superconducting bulk, it is argued that unconfined fermions would be localized within the (2+1)-dimensional layer, where their quantum fluctuations radiatively induce a Chern-Simons term, which is known to destroy the electric charge confinement and to promote the confinement of the magnetic instantons.