Berlin 2012 – scientific programme
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O: Fachverband Oberflächenphysik
O 84: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles VI (jointly with TT)
O 84.3: Talk
Friday, March 30, 2012, 11:15–11:30, HE 101
Ab-initio description of satellites in graphite — •Matteo Guzzo1, Lorenzo Sponza1, Christine Giorgetti1, Francesco Sottile1, Debora Pierucci2, Mathieu G. Silly2, Fausto Sirotti2, Joshua J. Kas3, John J. Rehr3, and Lucia Reining1 — 1Ecole Polytechnique, Palaiseau, FR — 2Synchrotron SOLEIL, Gif-sur-Yvette, FR — 3U. Washington, Seattle, USA
The GW method has been very successful in describing photoemission spectra in a variety of systems. In particular, GW is known to give good quasiparticle properties like band-gaps, but it has shown some limitations in the description of complex correlation effects like satellites. Satellite peaks in photoemission come from higher-order excitations and are still poorly studied in the valence bands. In perturbative GW the spectral function can describe additional features beside the quasiparticle peaks, but these satellites are known to be too weak and too low in energy, as it appears from calculations on the Homogeneous Electron Gas and some real materials. We have recently shown that including additional diagrams in the Green’s function (similarly to what has been done with the cumulant expansion) we obtain an excellent description of satellites series in the test case of bulk silicon [1], where GW is unable to cope. We now focus on a more complex system, i.e. graphite, with this same approach. Using our newly measured XPS valence data, we investigate the effects of anisotropies on satellites and give a prediction on the spectral changes following the transition towards a single graphene layer. Refs: [1] M. Guzzo et al., Phys. Rev. Lett. 107, 166401 (2011)