Criterion for the critical number of fermions and chiral symmetry breaking in anisotropic QED3

By analyzing the strength of a photon-fermion coupling using basic scattering processes we calculate the effect of a velocity anisotropy on the critical number of fermions at which mass is dynamically generated in planar quantum electrodynamics. This gives a quantitative criterion which can be used to locate a quantum critical point at which fermions are gapped and confined out of the physical spectrum in a phase diagram of various condensed-matter systems. We also discuss the mechanism of relativity restoration within the symmetric quantum-critical phase of the theory.