Disordered fermionic quantum critical points

Hennadii Yerzhakov; Joseph Maciejko

doi:10.1103/physrevb.98.195142

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arXiv · 1807.04845

Disordered fermionic quantum critical points

Hennadii Yerzhakov·Joseph Maciejko

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Abstract

We study the effect of 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 a double epsilon expansion. For $N\geq 2$ 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 $z>1$, and a finite Yukawa coupling between Dirac fermions and bosonic order parameter fluctuations. For $N\geq 7$ the disordered quantum critical point is described by a renormalization group fixed point of stable-focus type and exhibits oscillatory corrections to scaling.

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Hennadii Yerzhakov, Joseph Maciejko. 2018-07-12. Disordered fermionic quantum critical points. https://doi.org/10.1103/physrevb.98.195142

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