1205.6330 (K. Shizuya)

Structure and the Lamb-shift-like quantum splitting of the
pseudo-zero-mode Landau levels in bilayer graphene    [PDF]

K. Shizuya

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.

View original: http://arxiv.org/abs/1205.6330