Vladimir Falko, Lancaster University, Lancaster UK "Electronic properties of bilayer graphene, from 'high' to 'low' energies"

Oct 7, 2010, 4:30 pm6:00 pm
McDonnell A02


Event Description
I shall describe rich physics peculiar for elctrons in bilayer graphene at various scales of excitation energies. Using tight binding model for electrons in bilayers, I'll show that electrons in bilayer graphene (BLG) are Berry phase 2pi quasiparticles, with peculiar Landau level spectrum manifested in charactersitic sequencing of quantum Hall effect steps. I shall discuss the Lifshitz transition in BLG, which characterises the change in the topology of the electron Fermi line at low energies. Then, I shall describe BLG with externally broken symmetry: (a) the evolution of the Fermi line topology, the Landau level spectrum and Shoubnikov-de Haas oscillations in stretched/strained BLG; and (b) the interlayer asymmetry gap. Finally, subject to the lowest-energy physics of electron in bilayers, I shall discuss a possible spontaneous symmetry breaking in unperturbed BLG analysed using the renormalisation group theory for interaction taking into account all possible symmetry-breaking interaction channels.