Topological view on magnetic adatoms in graphene
arXiv:1102.4929 · doi:10.1103/PhysRevB.83.195404
Abstract
We study theoretically the physical properties of a magnetic impurity in graphene. Within the Anderson model for a very strong Coulomb interaction on the impurity, we start from the Slave-Boson method and introduce a topological picture consisting of a degree of a map and a winding number (WN) to analyze the phase shift and the occupation on the impurity. The occupation is linked to WN. For a generic normal metal we find a fractional WN. In contrast, the winding is accelerated by the relativistic dispersion of graphene at half-filling leading to an integer occupation. We show that the renormalization parameter that shifts the impurity level is insufficient to invert the sign of the energy level. Consequently, the state at half-filling is stable unless a gate voltage is tuned such that the Fermi level touches the edge of the broadened impurity level. Only in this case the zero field susceptibility is finite and shows a pronounced peak structure with the gate voltage.
9pages. 4 figures
References in corpus (14)
- Electric Field Effect in Atomically Thin Carbon Films
- The electronic properties of graphene
- Ultrathin epitaxial graphite: 2D electron gas properties and a route toward graphene-based nanoelectronics
- Imaging and Dynamics of Light Atoms and Molecules on Graphene
- Localized Magnetic States in Graphene
- Orthogonality catastrophe and Kondo effect in graphene
- Kondo Quantum Criticality of Magnetic Adatoms in Graphene
- Tuning Kondo physics in Graphene with gate voltage
- Localized Spins on Graphene
- Theory of Scanning Tunneling Spectroscopy of Magnetic Adatoms in Graphene
- Orbital selective and tunable Kondo effect of magnetic adatoms on graphene: Correlated electronic structure calculations
- Single or multi-flavor Kondo effect in graphene
- Localized magnetic states in biased bilayer and trilayer graphene
- Magneto-transport in impurity-doped few-layer graphene spin valve