Chiral symmetry breaking in three-dimensional QED with four-Fermi interactions at finite temperature

Using the 1N expansion, we study dynamical chiral symmetry breaking in three-dimensional QED with four-Fermi interactions at finite temperature. We numerically solve the temperature-dependent Schwinger-Dyson equation for the fermion self-energy and obtain the solutions which depend on momentum as well as temperature. We find a critical temperature above which chiral symmetry is restored. The results show the existence of a critical N which depends on temperature. The phase diagram for dynamical mass generation is shown in the N-g plane.