title: Electron spin resonance in presence of a magnetic impurity in graphene.
abstract: The ESR of a magnetic probe sited at a distance R from an adatom in graphene, interacting via a RKKY interaction, is studied. The spin relaxation rate of the magnetic probe in the case of pristine graphene satisfies a T(3) dependence for all temperatures at the Dirac point. However, away from the Dirac point a T(3) dependence is observed only for high temperatures unlike the Korringa behavior at low temperatures. Moreover, the zero-temperature relaxation rate of the pristine graphene demonstrates a quadratic dependence on the chemical potential. In the presence of the magnetic adatom hybridized with one site of the graphene sublattice we observe a dip in the relaxation rate away from the Dirac point. At the Dirac point a deviation from the T(3) dependence is observed. The presence of the Coulomb interaction U also modifies the zero-temperature relaxation rate when compared to that of pristine graphene. The transition from the magnetic state to the non-magnetic state is also characterized by a minimum in the relaxation rate.
authors: Departamento de Física-ICE, Universidade Federal do Amazonas, Manaus-AM, Brazil. angsula@ufam.edu.br
authors: Angsula
authors: A
authors: Ghosh
authors: J W M
authors: JW
authors: Pinto
authors: H O
authors: HO
authors: Frota
mesh_terms: D003198:Computer Simulation; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D060526:Magnetic Fields; D008956:Models, Chemical; D008958:Models, Molecular
chemical_list: D006108:Graphite