2012/05/31 by K. Shizuya · 1 citation
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.86.045431
published as Phys. Rev. B 86, 045431 (2012) · 12 pages, 4 figures, revtex; added references, to appear in PRB
arxiv created 2012/07/05 · arxiv updated 2012/10/25
In a magnetic field bilayer graphene supports an octet of zero-energy Landau levels with an extra twofold degeneracy in Landau orbitals n=0 and n=1. It is shown that this orbital degeneracy is lifted due to Coulombic quantum fluctuations of the valence band (the Dirac sea); this is a quantum effect analogous to the Lamb shift in the hydrogen atom. A detailed study is made of how these zero-energy levels evolve, with filling, into a variety of pseudo-zero-mode Landau levels in the presence of possible spin and valley breaking and Coulomb interactions, and a comparison is made with experimental results.