Confinement-Deconfinement Transition in 3-Dimensional QED

TL;DR

This paper investigates the confinement-deconfinement phase transition in 2+1 dimensional QED at finite temperature, identifying the transition as Berezinskii-Kosterlitz-Thouless type and deriving an effective field theory description.

Contribution

It introduces an effective scalar field theory for the Polyakov loop in 2+1D QED and analyzes the phase transition, including a one-loop calculation and critical temperature estimation.

Findings

The phase transition is of BKT type.

Effective theory reduces to Sine-Gordon model at large electron mass.

Critical temperature estimated as T_{crit} = e^2/8π(1 - e^2/12πm + ...).

Abstract

We argue that, at finite temperature, parity invariant non-compact electrodynamics with massive electrons in 2+1 dimensions can exist in both confined and deconfined phases. We show that an order parameter for the confinement-deconfinement phase transition is the Polyakov loop operator whose average measures the free energy of a test charge that is not an integral multiple of the electron charge. The effective field theory for the Polyakov loop operator is a 2-dimensional Euclidean scalar field theory with a global discrete symmetry $Z$, the additive group of the integers. We argue that the realization of this symmetry governs confinement and that the confinement-deconfinement phase transition is of Berezinskii-Kosterlitz-Thouless type. We compute the effective action to one-loop order and argue that when the electron mass $m$ is much greater than the temperature $T$ and dimensional coupling $e^2$, the effective field theory is the Sine-Gordon model. In this limit, we estimate the critical temperature, $T_{\rm crit.}=e^2/8\pi(1-e^2/12\pi m+\ldots)$.