Fine structure of chiral symmetry breaking in the QED₃ theory of underdoped high-T_c superconductors

We study the effects of the leading irrelevant perturbations on chiral symmetry breaking in the effective $QED_3$ theory of d-wave superconductor-insulator transition in underdoped cuprates. For weak symmetry breaking, the effect of a perturbation on energies of various insulating states can be classified according to its engineering dimension in the maximally symmetric theory. Considering the velocity anisotropy, repulsive interactions, and higher order derivatives we show that the insulating state with the lowest energy is the spin density wave.