Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 93: Graphen (organized by DS)

TT 93.9: Vortrag

Donnerstag, 19. März 2015, 11:45–12:00, H 0111

Charge and spin transport in graphene nanoribbons with adatoms and defects — •Flaviano José Dos Santos^1,2, Filipe Souza Mendes Guimarães^1,2, and Roberto Bechara Muniz¹ — ¹Institute of Physics, Universidade Federal Fluminense, Niterói, Brazil — ²Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

Several features of spintronic systems are related to the spin-orbit coupling (SOC). Since SOC is relatively small in carbon atoms, several studies have been conducted in order to obtain a way to increase SOC in graphene (e.g., via adsorption of impurities on the graphene surface), which would allow to employ graphene as a basic material for spintronic devices. We have studied the charge and spin transport in graphene nanoribbons, in the linear response regime, affected by the presence of defects (vacancies and edge constrictions) and adatoms. We used effective models for light and heavy adsorbed impurities, some of them inducing enhancement of the SOC [1]. The results are obtained through a combination of analytical and numerical derivations. We investigated the impact of impurity concentration on the establishment of topologically protected edge states giving rise to a spin polarized current flux through the sample. In addition to conductance, local densities of states and current distribution calculations, we also simulate maps of real space local conductance properties for dual-probe Scanning Tunneling Microscope [2] setups on these systems. [1] C. Week et al., Phys. Rev. X 1, 021001 (2011). [2] M. Settnes et al., Phys. Rev. Lett. 112, 096801 (2014). Funding: Capes and CNPq (Brazil).