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Evento

Título:: Tatiana Rappoport: Spin-related effects in graphene
quando:: 14.11.2012 11.00 h
onde:: Matéria Condensada Teórica - Niterói
Categoria:: Seminários

Descrição

Spin-related effects in graphene with adatoms

Tatiana G. Rappoport (UFRJ)

In this talk, I will discuss the consequences of doping graphene with magnetic adatoms. The vanishing density of states of graphene close to the Dirac point is responsible for two effects: adatoms can easily form local magnetic moments; also the interaction between these magnetic moments and the spin of carriers can be surprisingly strong and controlled my gating. Both effects enhance the magnetic properties of graphene in the presence of adatoms. Moreover, when the layer is doped with a large number of adatoms, it is possible to modify the electronic properties of the system by controlling its magnetization. I will show that a random distribution of magnetic adatoms can open a robust gap in the electronic spectrum of graphene and its size can be controlled by both temperature and external magnetic field. Finally, I will discuss the possibility of generating spin currents in graphene doped with non-magnetic adatoms. When heavy atoms are adsorbed on top of graphene, their strong spin-orbit interaction can give rise to skew scattering, where the scattering amplitude of the carriers depends on their spin state. This asymmetry in scattering can lead to extrinsic spin Hall effect in graphene.