Universal Conductance Fluctuations in Dirac Materials in the Presence of Long-range Disorder

作者：Rossi E^*; Bardarson J H; Fuhrer M S; Das Sarma S

来源：Physical Review Letters, 2012, 109(9): 096801.

DOI：10.1103/PhysRevLett.109.096801

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.

• 出版日期2012-8-27