Gate-Tunable Exchange Coupling Between Cobalt Clusters on Graphene

Abstract

We use spin-density-functional theory (SDFT) ab initio calculations to theoretically explore the possibility of achieving useful gate control over exchange coupling between cobalt clusters placed on a graphene sheet. By applying an electric field across supercells we demonstrate that the exchange interaction is strongly dependent on gate voltage, but find that it is also sensitive to the relative sublattice registration of the cobalt clusters. We use our results to discuss strategies for achieving strong and reproducible magneto-electric effects in graphene/transition-metal hybrid systems.

17 pages, 15 figures

References in corpus (13)

• The electronic properties of graphene
• Energy Gaps in Graphene Nanoribbons
• Half-Metallic Graphene Nanoribbons
• Doping graphene with metal contacts
• Dynamical polarization of graphene at finite doping
• Graphite and graphene as perfect spin filters
• Friedel oscillations, impurity scattering and temperature dependence of resistivity in graphene
• RKKY in half-filled bipartite lattices: graphene as an example
• Diluted Graphene Antiferromagnet
• Theoretical prediction of perfect spin filtering at interfaces between close-packed surfaces of Ni or Co and graphite or graphene
• RKKY Interaction in Graphene from Lattice Green's Function
• Ordering of magnetic impurities and tunable electronic properties of topological insulators
• Electron-Electron Interactions on the Edge States of Graphene: A Many Body Configuration Interaction Study