title: Localized spins on graphene.
abstract: The problem of a magnetic impurity, atomic or molecular, absorbed on top of a carbon atom in otherwise clean graphene is studied using the numerical renormalization group. The spectral, thermodynamic, and scattering properties of the impurity are described in detail. In the presence of a small magnetic field, the low-energy electronic features of graphene make it possible to inject spin-polarized currents through the impurity using a scanning tunneling microscope. Furthermore, the impurity scattering becomes strongly spin dependent and for a finite impurity concentration it leads to spin-polarized bulk currents and a large magnetoresistance. In gated graphene the impurity spin is Kondo screened at low temperatures. However, at temperatures larger than the Kondo temperature, the anomalous magnetotransport properties are recovered.
authors.affiliation: Centro Atómico Bariloche and Instituto Balseiro, 8400 Bariloche, Argentina.
authors.forename: P S
authors.initials: PS
authors.lastname: Cornaglia
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Usaj
authors.forename: C A
authors.initials: CA
authors.lastname: Balseiro