J. Munárriz, C. Gaul, A. V. Malyshev, P. A. Orellana, C. A. Müller, F. Domínguez-Adame
Since the pioneering work by Esaki, quantum tunneling and negative differential resistance (NDR) have been the underlying principle of operation of various quantum devices. The principle implies that the electric current through a device increases when the chemical potential in one of the leads approaches an energy level of the device. However, if the energy level depends on the applied voltage the current can decrease drastically with a further increase of the voltage, resulting in the NDR. Such conductance anomaly can be observed in semiconductor heterostructures, molecular systems and at the atomic scale. Here we address a novel device based on graphene, whose remarkable charge transport properties and long spin-coherence length makes it a promising material for spintronics. We consider a composite superlattice comprising a set of ferromagnetic insulator strips deposited on top of a graphene nanoribbon (GNR). We calculate current-voltage characteristics of the device and predict spin-filtering effect and strong spin-dependent NDR.
View original:
http://arxiv.org/abs/1210.8277
No comments:
Post a Comment