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 possible to inject spin polarized currents through the impurity using a scanning tunneling microscope (STM). 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.

4+ pages, 4 figures. Added references

References in corpus (7)

• Electric Field Effect in Atomically Thin Carbon Films
• Room-Temperature Quantum Hall Effect in Graphene
• The numerical renormalization group method for quantum impurity systems
• Spin transport in proximity induced ferromagnetic graphene
• Spin currents in rough graphene nanoribbons: Universal fluctuations and spin injection
• Localized Magnetic States in Graphene
• STM conductance of Kondo impurities on open and structured surfaces