Edge and bulk components of lowest-Landau-level orbitals, correlated fractional quantum Hall effect incompressible states, and insulating behavior in finite graphene samples

Abstract

Many-body calculations of the total energy of interacting Dirac electrons in finite graphene samples exhibit joint occurrence of cusps at angular momenta corresponding to fractional fillings characteristic of formation of incompressible (gapped) correlated states (nu=1/3 in particular) and opening of an insulating energy gap (that increases with the magnetic field) at the Dirac point, in correspondence with experiments. Single-particle basis functions obeying the zigzag boundary condition at the sample edge are employed in exact diagonalization of the interelectron Coulomb interaction, showing, at all sizes, mixed equal-weight bulk and edge components. The consequent depletion of the bulk electron density attenuates the fractional-quantum-Hall-effect excitation energies and the edge charge accumulation results in a gap in the many-body spectrum.

8 pages with 7 figures. REVTEX4. For related publications, see http://www.prism.gatech.edu/~ph274cy

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Cited by in corpus (4)

• Unique nature of the lowest Landau level in finite graphene samples with zigzag edges: Dirac electrons with mixed bulk-edge character
• Theory of integer quantum Hall effect in insulating bilayer graphene
• Graphene flakes with defective edge terminations: Universal and topological aspects, and one-dimensional quantum behavior
• The triggering role of carrier mobility in the fractional quantum Hall effect-evidence in graphene