Landau level degeneracy and quantum Hall effect in a graphite bilayer

2005/10/31 by Edward McCann, Vladimir I. Fal'ko · 2 citations
Physics and Astronomy · Mathematics · #cond-mat.mes-hall #hep-th #math-ph #math.MP

paper · pdf · doi:10.1103/physrevlett.96.086805

published as Phys.Rev.Lett. 96 (2006) 086805 · 4 pages, 4 eps figures

arxiv created 2006/03/03 · arxiv updated 2009/12/01

Abstract

We derive an effective two-dimensional Hamiltonian to describe the low energy electronic excitations of a graphite bilayer, which correspond to chiral quasiparticles with a parabolic dispersion exhibiting Berry phase 2π. Its high-magnetic-field Landau level spectrum consists of almost equidistant groups of four-fold degenerate states at finite energy and eight zero-energy states. This can be translated into the Hall conductivity dependence on carrier density, σ_xy(N), which exhibits plateaus at integer values of 4e²/h and has a ``double'' 8e²/h step between the hole and electron gases across zero density, in contrast to (4n+2)e²/h sequencing in a monolayer.

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