Electron confinement in graphene with gate-defined quantum dots

We theoretically analyse the possibility to electrostatically confine electrons in circular quantum dot arrays, impressed on contacted graphene nanoribbons by top gates. Utilising exact numerical techniques, we compute the scattering efficiency of a single dot and demonstrate that for small-sized scatterers the cross-sections are dominated by quantum effects, where resonant scattering leads to a series of quasi-bound dot states. Calculating the conductance and the local density of states for quantum dot superlattices, we show that the resonant carrier transport through such graphene-based nanostructures can be easily tuned by varying the gate voltage. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim