Nontrivial infrared structure in (2+1)-dimensional quantum electrodynamics

We show that the gauge-fermion interaction in multiflavor (2 + 1)-dimensional quantum electrodynamics with a finite infrared cutoff is responsible for non-Fermi-liquid behavior in the infrared, in the sense of leading to the existence of a nontrivial fixed point at zero momentum, as well as to a significant slowing down of the running of the coupling at intermediate scales as compared with previous analyses on the subject. Both these Features constitute deviations from Fermi-liquid theory. Our discussion is based on the leading-1/N resummed solution for the wave-function renormalization of the Schwinger-Dyson equations. The present work completes and confirms the expectations of an earlier work by two of the authors (I.J.R.A. and N.E.M.) on the nontrivial infrared structure of the theory.