Relativity Restored: Dirac Anisotropy in QED$_3$

Abstract

We show that at long lengthscales and low energies and to leading order in 1/N expansion, the anisotropic QED in 2+1 dimensions renormalizes to an isotropic limit. Consequently, the (Euclidean) relativistic invariance of the theory is spontaneously restored at the isotropic critical point, characterized by the anomalous dimension exponent of the Dirac fermion propagator $η$. We find $η=16/3π^2 N$.