Physical Review Letters
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.
Rossi, E., Bardarson, J. H., Fuhrer, M. S., & Sarma, S. D. (2012). Universal conductance fluctuations in Dirac materials in the presence of long-range disorder. Physical review letters, 109(9), 096801.