▎ 摘　　要

This study is devoted to potential applications of graphene nanostructures (GNRs) in future electronics and spintronics. This problem is related with the impact of geometrical and magnetic features of interfaces between contacts and the GNR on electrical performance of the device. The present approach combines the tight-binding model and Green's function technique. It makes possible to put end-contacted and side-contacted arrangements on an equal footing, and understand their effect on conductance and giant magnetoresistance (GMR), depending on: aspect ratio, current orientation, gate voltage and dephasing. It turns out that at low gate voltages, dephasing processes may enhance the GMR effect, and that for short nanoribbons the end-contacted geometry leads to the highest conductance. Long semiconducting armchair graphene nanoribbons, in turn, may reveal a sizeable inverse GMR effect. Some additional insight into the scalability of GNRs, for the spin-dependent transport, is also provided. [GRAPHICS] End-contacted zigzag GNR with infinite source and drain electrodes (top and bottom) and a fictitious dephasing contact (left). (c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim