Phase Transitions in lattice QED

TL;DR

This paper investigates phase transitions in lattice QED, revealing monopole phenomena, boundary condition effects, and topological excitations, with findings indicating both first and second order transitions depending on the model and conditions.

Contribution

It provides new insights into the nature of phase transitions in lattice QED, including effects of boundary conditions and topological excitations, and relates different models through their phase behavior.

Findings

Monopole percolation linked to monopole condensation in pure gauge QED.

Boundary conditions influence the order of phase transitions in lattice QED.

Topological excitations may cause intriguing behaviors near phase transitions.

Abstract

The main objective of the work presented here is to understand the appearance of phase transitions in pure gauge and scalar lattice QED. Main results are as follows: Pure gauge compact QED with PBC shows a monopole percolation phenomena coupled to the monopole condensation. Pure gauge compact QED with Fixed Boundary Conditions (spherical topology) shows a behaviour compatible with a second order phase transition The $\gamma\to\infty$ limit of Non Compact Scalar QED with PBC is related to the Villain form of compact QED and also to the Loop Model for QED, showing a first order phase transition. Numerical a analysis of a third rank abelian Z(2) theory shows an intriguing behaviour over the phase transition that may be originated by point-like topological excitations.