Condition for the emergence of a bulk Fermi arc in disordered Dirac-fermion systems

TL;DR

This paper investigates how different types of disorder affect low-energy properties of tilted Dirac fermions, revealing conditions under which a bulk Fermi arc emerges in disordered two-dimensional systems.

Contribution

It provides a renormalization group analysis of disorder effects, identifying conditions for the emergence of a bulk Fermi arc in tilted Dirac-fermion systems.

Findings

Interorbital disorder induces corrections to density of states and specific heat.

Intraorbital disorder can lead to a strongly disordered phase with a Fermi arc.

Conditions for Fermi arc emergence depend on the interplay of multiple disorder types.

Abstract

We present a renormalization group analysis of the disorder effects on the low-energy behaviors of twodimensional tilted Dirac-fermion systems, in which the fermions have two distinct orbitals unrelated by any symmetry. Four types of disordered potential, two interorbital and two intraorbital, are considered. If there is only one type of interorbital disorder, the fermion-disorder scattering induces logarithmic or power-law corrections to the fermion density of states and specific heat. In contrast, the intraorbital disorder can turn the system into a strongly disordered phase. In this disordered phase, calculations based on self-consistent Born approximation reveal that the Dirac point is destroyed and replaced by a bulk Fermi arc. We also study the interplay of four types of disorder, and find that the Dirac point can either remain intact or give place to a Fermi arc. We obtain the condition for the emergence of a Fermi arc in this case. Our results indicate that disorders can result in rich low-energy properties of tilted Dirac fermions.