Critical fixed points in class D superconductors

Abstract

We study in detail a critical line on the phase diagram of the Cho-Fisher network model separating three different phases: metallic and two distinct localized phases with different quantized thermal Hall conductances. This system describes non-interacting quasiparticles in disordered superconductors that have neither time-reversal nor spin-rotational invariance. We find that in addition to a tricritical fixed point $W_T$ on that critical line there exist an additional repulsive fixed point $W_N$ (where the vortex disorder concentration $W_N<W_T$), which splits RG flow into opposite directions: toward a clean Ising model at W=0 and toward $W_T$.

3 pages, one figure

References in corpus (3)

• The two-dimensional random-bond Ising model, free fermions and the network model
• Density of quasiparticle states for a two-dimensional disordered system: Metallic, insulating, and critical behavior in the class D thermal quantum Hall effect
• Universal critical exponent in class D superconductors

Cited by in corpus (8)

• Effective mass and tricritical point for lattice fermions localized by a random mass
• Absence of a metallic phase in charge-neutral graphene with a random gap
• Temperature enhancement of thermal Hall conductance quantization
• Multicriticality of Two-dimensional Class D Disordered Topological Superconductors
• Renormalization group analysis of Dirac fermions with random mass
• Localization properties of random-mass Dirac fermions from real-space renormalization group
• Genuine topological Anderson insulator from impurity induced chirality reversal
• Majorana-metal transition in a disordered superconductor: percolation in a landscape of topological domain walls