A model to study finite-size and magnetic effects on the phase transition of a fermion interacting system

Abstract

We present a model to study the effects from external magnetic field, chemical potential and finite size on the phase structures of a massive four- and six-fermion interacting systems. These effects are introduced by a method of compactification of coordinates, a generalization of the standard Matsubara prescription. Through the compactification of the z-coordinate and of imaginary time, we describe a heated system with the shape of a film of thickness L, at temperature [Formula: see text] undergoing first- or second-order phase transition. We have found a strong dependence of the temperature transition on the coupling constants [Formula: see text] and [Formula: see text]. Besides inverse magnetic catalysis and symmetry breaking for both kinds of transition, we have found an inverse symmetry breaking phenomenon with respect to first-order phase transition.