NON FERMI-LIQUID BEHAVIOR IN SEMIMETALS - APPLICATIONS TO THE FULLERENES

In a variety of semimetals with vanishing density of slates a the Fermi level, the low energy electronic stales are described by an effective Dirac equation, instead of the more conventional effective mass approximation (equivalent to Schrodinger equation). When this happens, electron-electron interactions give rise to anomalous features, which differ from those of conventional metals and insulators. A comprehensive discussion of these effects is presented, making use of the fact that Dirac electrons interacting through Coulomb forces lead to a well defined, renormalizable, quantum field theory, which has many similarities to quantum, electrodynamics. The most remarkable feature is the absence of a coherent quasiparticle pole, like in 1D Luttinger liquids.