Nodal arc of disordered Dirac fermions and non-Hermitian band theory

Abstract

Disordered Dirac fermions have been studied in a variety of contexts, including quantum Hall transitions, surface states of topological insulators, and graphene. Here, the authors study a new Dirac system in which the two components of the Dirac fermion are unrelated by symmetry and, hence, disorder results in two different quasiparticle lifetimes. It is demonstrated that disorder generates a nodal arc replacing the original Dirac point, thus leading to a new universality class.