The Aoki phase for N_f=2 Wilson fermions revisited

TL;DR

This paper revisits the Aoki phase in two-flavor Wilson fermion lattice QCD, confirming its presence at certain couplings and temperatures through numerical simulations, and clarifying its phase boundaries.

Contribution

It provides a detailed numerical analysis of the Aoki phase at various couplings and temperatures, updating previous understanding of its existence and boundaries.

Findings

Aoki phase confirmed at $eta=4.0$ and $eta=4.3$ at zero temperature

Aoki phase not observed at $eta=4.6$ and $eta=5.0$ at zero temperature

Aoki phase exists at $eta=4.6$ at non-zero temperature

Abstract

We report on a numerical reinvestigation of the Aoki phase in full lattice QCD with two flavors of unimproved Wilson fermions. For zero temperature the Aoki phase can be confirmed at inverse coupling $\beta=4.0$ and $\beta=4.3$, but not at $\beta=4.6$ and $\beta=5.0$. At non-zero temperature the Aoki phase was found to exist also at $\beta=4.6$.