Electron-Electron Interactions on the Edge States of Graphene: A Many Body Configuration Interaction Study

Abstract

We have studied zigzag and armchair graphene nano ribbons (GNRs), described by the Hubbard Hamiltonian using quantum many body configuration interaction methods. Due to finite termination, we find that the bipartite nature of the graphene lattice gets destroyed at the edges making the ground state of the zigzag GNRs a high spin state, whereas the ground state of the armchair GNRs remains a singlet. Our calculations of charge and spin densities suggest that, although the electron density prefers to accumulate on the edges, instead of spin polarization, the up and down spins prefer to mix throughout the GNR lattice. While the many body charge gap results in insulating behavior for both kinds of GNRs, the conduction upon application of electric field is still possible through the edge channels because of their high electron density. Analysis of optical states suggest differences in quantum efficiency of luminescence for zigzag and armchair GNRs, which can be probed by simple experiments.

5 pages, 4 figures

References in corpus (13)

• Two Dimensional Atomic Crystals
• Energy Gaps in Graphene Nanoribbons
• The structure of suspended graphene sheets
• Half-Metallic Graphene Nanoribbons
• Ultrathin epitaxial graphite: 2D electron gas properties and a route toward graphene-based nanoelectronics
• Room-Temperature Quantum Hall Effect in Graphene
• Electronic States of Graphene Nanoribbons
• Peculiar Width Dependence of the Electronic Property of Carbon Nanoribbons
• Spin Filtered Edge States and Quantum Hall Effect in Graphene
• Electronic transport and quantum Hall effect in bipolar graphene p-n-p junction
• Edge state on hydrogen-terminated graphite edges investigated by scanning tunneling microscopy
• Electron-electron interaction effects on optical excitations in semiconducting single-walled carbon nanotubes
• Gauge field for edge state in graphene

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• Spin-spin correlations of magnetic impurities in graphene
• Massless Fermions on a half-space: The curious case of 2+1-dimensions
• Boundary Ferromagnetism in Zigzag Edged Graphene
• Kekulé valence bond order in the Hubbard model on the honeycomb lattice with possible lattice distortions for graphene
• Effect of edge structures on elastic modulus and fracture of graphene nanoribbons under uniaxial tension