On the thermodynamics of the 2+1 dimensional Gross-Neveu model with complex chemical potential

TL;DR

This paper investigates the thermodynamics of the 2+1D Gross-Neveu model with complex chemical potential, revealing insights into anyon-like excitations, symmetry breaking, and phase transitions.

Contribution

It introduces a unified approach to study real and imaginary chemical potentials, linking symmetry breaking to anyon deconfinement and providing analytical results at transition points.

Findings

Imaginary chemical potential probes anyon-like excitations.

Discrete Z-symmetry breaking signals anyon deconfinement.

Analytical free-energy results at phase transition points.

Abstract

We study the thermodynamics of the 2+1 dimensional Gross-Neveu model in the presence of a chemical potential by introducing a representation for the canonical partition function which encodes both real and imaginary chemical potential cases. It is pointed out that the latter case probes the thermodynamics of the possible anyon-like excitations in the spectrum. It is also intimately connected to the breaking of the discrete Z-symmetry of a U(1) gauge theory coupled to the Gross-Neveu model at finite temperature, which we interpret as signaling anyon deconfinement. Finally, the chiral properties of the model in the presence of an imaginary chemical potential are discussed and analytical results for the free-energy density at the transition points are presented.