Surface modes and parity violation in Schwinger model on the lattice

TL;DR

This paper explores the phase diagram of the lattice Schwinger model with Wilson fermions, revealing a parity-violating phase at various couplings through Hartree-Fock approximation analysis.

Contribution

It provides the first Hartree-Fock based analysis of the lattice Schwinger model's phase structure, including parity violation and electric field behavior.

Findings

Parity violating phase exists at weak and intermediate couplings

Hartree-Fock vacuum sustains a nonzero electric field in the broken phase

Phase structure with two flavors is also discussed

Abstract

The phase diagram of the Schwinger model on the lattice with Wilson fermions is investigated in the Hartree-Fock approximation. In case of single flavour (not directly amenable to simulations), the calculation indicates the existence of the parity violating phase at both weak and intermediate-to-strong couplings. Hartree-Fock vacuum sustains a nonzero electric field in this broken phase. The phase structure of the model with two flavours is also discussed.