Disordered fermionic quantum critical points

<!--StartFragment-->We study the effect of short-range quenched disorder on the semimetal-superconductor quantum phase transition in a model of two-dimensional Dirac semimetal with N flavors of two-component Dirac fermions, using perturbative renormalization group methods at one-loop order in 4-ε spatial and ε_τ time dimensions. Depending on the value of N, the model is applicable to topological insulators (odd N), graphene (N=4), and possibly other systems and type of transitions. For N≥2 we find that the Harris-stable clean critical behavior gives way, past a certain critical disorder strength, to a finite-disorder critical point characterized by non-Gaussian critical exponents, a noninteger dynamic critical exponent, and a finite Yukawa coupling between Dirac fermions and bosonic order parameter fluctuations. For sufficiently large N the disordered quantum critical point is described by a renormalization group fixed point of stable-focus type and exhibits oscillatory corrections to scaling.<!--EndFragment-->