Valence Electron Photoemission Spectrum of Semiconductors: Ab Initio Description of Multiple Satellites

Matteo Guzzo (1, 2) , Giovanna Lani (1, 2) , Francesco Sottile (1, 2) , Pina Romaniello (3, 2) , Matteo Gatti (2, 4) , Joshua J. Kas (5) , John J. Rehr (2, 5) , Mathieu G. Silly (6) , Fausto Sirotti (6) , Lucia Reining (1, 2)

1 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory
2 ETSF - European Theoretical Spectroscopy Facility
3 AGR-LPT - Agrégats (LPT)
4 Nano-Bio Spectroscopy Group
5 Department of Physics, University of Washington
6 SSOLEIL - Synchrotron SOLEIL

The experimental valence band photoemission spectrum of semiconductors exhibits multiple satellites that cannot be described by the GW approximation for the self-energy in the framework of many-body perturbation theory. Taking silicon as a prototypical example, we compare experimental high energy photoemission spectra with GW calculations and analyze the origin of the GW failure. We then propose an approximation to the functional differential equation that determines the exact one-body Green's function, whose solution has an exponential form. This yields a calculated spectrum, including cross sections, secondary electrons, and an estimate for extrinsic and interference effects, in excellent agreement with experiment. Our result can be recast as a dynamical vertex correction beyond GW, giving hints for further developments.

Domaines: Autre [cond-mat.other]; Physique Quantique [quant-ph]

Matteo Guzzo, Giovanna Lani, Francesco Sottile, Pina Romaniello, Matteo Gatti, et al.. Valence Electron Photoemission Spectrum of Semiconductors: Ab Initio Description of Multiple Satellites. Physical Review Letters, 2011, 107 (16), pp.166401. ⟨10.1103/PhysRevLett.107.166401⟩. ⟨hal-00659118⟩