title: Universal conductance fluctuations in Dirac materials in the presence of long-range disorder.
abstract: We study quantum transport in Dirac materials with a single fermionic Dirac cone (strong topological insulators and graphene in the absence of intervalley coupling) in the presence of non-Gaussian long-range disorder. We show, by directly calculating numerically the conductance fluctuations, that in the limit of very large system size and disorder strength, quantum transport becomes universal. However, a systematic deviation away from universality is obtained for realistic system parameters. By comparing our results to existing experimental data on 1/f noise, we suggest that many of the graphene samples studied to date are in a nonuniversal crossover regime of conductance fluctuations.
authors.affiliation: Department of Physics, College of William and Mary, Williamsburg, Virginia 23187, USA.
authors.forename: E
authors.initials: E
authors.lastname: Rossi
authors.forename: J H
authors.initials: JH
authors.lastname: Bardarson
authors.forename: M S
authors.initials: MS
authors.lastname: Fuhrer
authors.forename: S
authors.initials: S
authors.lastname: Das Sarma