Robust mesoscopic fluctuations in disordered graphene

The temperature dependence of the mesoscopic conductance fluctuations is investigated for disordered graphene. The fluctuations are generated by varying either magnetic field or carrier density (via a back-gate). Very different temperature cut-offs are found for these two types of fluctuations, with the density-induced features persisting to much higher temperatures (beyond 100 K, even) than those observed when sweeping magnetic field. The robust character of the density-dependent fluctuations may cause them to play an important role in determining the operation of future graphene nanodevices, particularly as device sizes are reduced to the nanoscale.