Emergence of massless Dirac quasiparticles in correlated hydrogenated graphene with broken sublattice symmetry

Abstract

Using the variational cluster approximation (VCA) and the cluster perturbation theory, we study the finite temperature phase diagram of a half-depleted periodic Anderson model on the honeycomb lattice at half filling for a model of graphone, i.e., single-side hydrogenated graphene. The ground state of this model is found to be ferromagnetic (FM) semi-metal. The spin wave dispersion in the FM state is linear in momentum at zero temperature but becomes quadratic at finite temperatures, implying that the FM state is fragile against thermal fluctuations. Indeed, our VCA calculations find that the paramagnetic (PM) state dominates the finite temperature phase diagram. More surprisingly, we find that massless Dirac quasiparticles with the linear energy dispersion emerge at the Fermi energy upon introducing the electron correlation $U$ at the impurity sites in the PM phase. The Dirac Fermi velocity is found to be highly correlated to the quasiparticle weight of the emergent massless Dirac quasiparticles at the Fermi energy and monotonically increases with $U$. These unexpected massless Dirac quasiparticles are also examined with the Hubbard-I approximation and the origin is discussed in terms of the spectral weight redistribution involving a large energy scale of $U$. Considering an effective quasiparticle Hamiltonian which reproduces the single-particle excitations obtained by the Hubbard-I approximation, we argue that the massless Dirac quasiparticles are protected by the electron correlation. Our finding is therefore the first example of the emergence of massless Dirac quasiparticles due to dynamical electron correlations without breaking any spatial symmetry. The experimental implications of our results for graphone as well as a graphene sheet on transition metal substrates are also briefly discussed.

arXiv comment28 pages, 21 figures, to be published in Phys. Rev. B

References in corpus (24)

• The electronic properties of graphene
• Two-Dimensional Gas of Massless Dirac Fermions in Graphene
• Control of graphene's properties by reversible hydrogenation
• Graphane: a two-dimensional hydrocarbon
• Electron-Electron Interactions in Graphene: Current Status and Perspectives
• Quantum spin-liquid emerging in two-dimensional correlated Dirac fermions
• Impurity induced spin-orbit coupling in graphene
• The spectral weight of the Hubbard model through cluster perturbation theory
• Variational cluster approach to correlated electron systems in low dimensions
• Absence of a Spin Liquid Phase in the Hubbard Model on the Honeycomb Lattice
• Pinning the order: the nature of quantum criticality in the Hubbard model on honeycomb lattice
• RKKY in half-filled bipartite lattices: graphene as an example
• Optimal Hubbard models for materials with nonlocal Coulomb interactions: graphene, silicene and benzene
• Fermionic quantum criticality in honeycomb and $\pi$-flux Hubbard models: Finite-size scaling of renormalization-group-invariant observables from quantum Monte Carlo
• Universal quantum criticality in the metal-insulator transition of two-dimensional interacting Dirac electrons
• Spin-orbit coupling in hydrogenated graphene
• Dirac half-metal in a triangular ferrimagnet
• Exchange interactions and frustrated magnetism in single-side hydrogenated and fluorinated graphene
• Evidence for hidden fermion that triggers high-temperature superconductivity in cuprates
• Kondo--lattice-like effects of hydrogen in transition metals
• Topological aspects of graphene: Dirac fermions and the bulk-edge correspondence in magnetic fields
• Chiral symmetry and its manifestation in optical responses in graphene: interaction and multi-layers
• Ferromagnetism of magnetic impurities coupled indirectly via conduction electrons: Insights from various theoretical approaches
• Antiferromagnetism versus Kondo screening in the two-dimensional periodic Anderson model at half filling: Variational cluster approach

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