Seminars Archive

Unravelling the electronic structure of intercalated graphite: a key to graphene and single-wall carbon nanotubes

Abstract
Understanding the unique low energy electronic structure of carbon systems is the key for their peculiar properties. In this contribution we show how to nravel electronic correlations in pristine [1] and intercalated (stage I, II and III) graphite single crystals from the quasi particle dispersion of the valence band electrons using a combined angle resolved photoemission and theoretical approach. We report the full three-dimensional renormalized band dispersion and the strength and angular dependence of the electron-electron and electron-phonon interactions as a function of doping. We will show that these results enable us to accurately determine key properties, such as Fermi velocities, effective masses and electron-electron and electron-phonon coupling constants in graphite and weakly coupled graphene layers without substrate interaction. We highlight the implications of our results for the understanding of transport, superconductivity and the resonance Raman effect in a wide range of sp2 hybridised carbon systems such as graphene, graphite and single wall carbon nanotubes. If time provides we will discuss the synthesis and electronic structure of graphene monolayers grown on Ni(111). We discuss a hybridization induced “kink‿ like features in the quasiparticle dispersion of the pi bands of graphen. which indicates a strong hybridization between the pi and d states of graphene and nickel. Upon deposition and gradual intercalation of potassium atoms into the graphene/Ni(111) interface, the “kink‿-like structure becomes less pronounced pointing at a potassium mediated attenuation of the interaction between the graphene and the substrate. [1] A.Grüneis et al. Phys. Rev. Lett. 100, 037601 (2008)