Doped single-walled carbon nanotubes and low-mobility graphene: impact of disorder and dopants on electronic magnetotransport

The impact of disorder introduced by intentional and unintentional (environmental) dopants on the charge transport has been investigated in boron- and nitrogen-doped single-walled carbon nanotubes, and in low-mobility monolayer graphene. For doped single-walled nanotubes a theoretically not predicted plateau-like region and onsets of oscillatory behaviour in the conductance for boron- and nitrogen-doped nanotubes were observed, respectively. The oscillatory behaviour suggests interplay between the dopants and the helical movement of charges along the tube due to the magnetic field. For low-mobility graphene the simultaneous appearance of the filling-factor 2 and 3 plateau was observed in the Quantum-Hall regime. This is attributed to an electron-spin-isospin interaction mediated through the high disorder. (c) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim