Impurity-induced magnetic moments on the graphene-lattice Hubbard model: an inhomogeneous cluster DMFT study

Abstract

Defect-induced magnetic moments are at the center of the research effort on spintronic applications of graphene. Here we study the problem of a nonmagnetic impurity in graphene with a new theoretical method, inhomogeneous cluster dynamical mean field theory (I-CDMFT), which takes into account interaction-induced short-range correlations while allowing long-range inhomogeneities. The system is described by a Hubbard model on the honeycomb lattice. The impurity is modeled by a local potential. For a large enough potential, interactions induce local antiferromagnetic correlations around the impurity and a net total spin $\frac{1}{2}$ appears, in agreement with Lieb's theorem. Bound states caused by the impurity are visible in the local density of states (LDOS) and have their energies shifted by interactions in a spin-dependent way, leading to the antiferromagnetic correlations. Our results take into account dynamical correlations; nevertheless they qualitatively agree with previous mean-field and density functional theory (DFT) studies. Moreover, they provide a relation between impurity potential and on-site repulsion $U$ that could in principle be used to determine experimentally the value of $U$.

11 pages, 9 figures

References in corpus (21)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Graphene Spintronics
• Magnetism in Graphene Induced by Single-Atom Defects
• Emergence of magnetism in graphene materials and nanostructures
• Magnetic Correlations at Graphene Edges
• Disorder Induced Localized States in Graphene
• Tunneling Spin Injection into Single Layer Graphene
• Tunneling Spin Injection into Single Layer Graphene (Supplementary Information)
• Magnetism in Disordered Graphene and Irradiated Graphite
• Resonant scattering by realistic impurities in graphene
• Absence of a Spin Liquid Phase in the Hubbard Model on the Honeycomb Lattice
• RKKY in half-filled bipartite lattices: graphene as an example
• Antiferromagnetic Order of Strongly Interacting Fermions in a Trap: Real-Space Dynamical Mean-Field Analysis
• Interacting Dirac Fermions on Honeycomb Lattice
• Electron waves in chemically substituted graphene
• Nonmagnetic-Defect-Induced Magnetism in Graphene
• Dynamical Mean Field Study of The Dirac Liquid
• Interactions and magnetic moments near vacancies and resonant impurities in graphene
• Local density of states and scanning tunneling currents in graphene
• Magnetic field induced semimetal-to-canted-antiferromagnet transition on the honeycomb lattice

Cited by in corpus (4)

• Mott transition and magnetism on the anisotropic triangular lattice
• Electronic interactions in a vacancy-engineered honeycomb lattice: Transition from a nodal-line semimetal to a magnetic insulator
• Coherent cellular dynamical mean-field theory: a real-space quantum embedding approach to disorder in strongly correlated electron systems
• Formation of CuO${}_2$ sublattices by suppression of interlattice correlations in tetragonal CuO