Regensburg 2010 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 60: Poster Session III (Methods: Atomic and electronic structure; Methods: electronic structure theory; Methods: Molecular simulations and statistical mechanics; Methods: Sanning probe techniques; Methods: other (experimental); Methods: other (theory) )

O 60.35: Poster

Mittwoch, 24. März 2010, 17:45–20:30, Poster B2

Real-time simulation of Si(001) 2PPE spectra — •Henning Husser and Eckhard Pehlke — Institut für Theoretische Physik und Astrophysik, Universität Kiel, 24098 Kiel, Germany

The photo-current induced by a fs laser-pulse is simulated by real-time ab initio TDDFT molecular dynamics. The electronic structure of the Si(001) surface is described within density-functional theory using a slab geometry. To account for the finite escape depth of the photo-electrons emitted from a solid surface like Si(001), an optical potential acting on the conduction states only is included in the integration of the time dependent Kohn-Sham equations. The calculation is carried through at frozen-in effective potential. We note, however, that the time-dependent Kohn-Sham equations could be integrated self-consistently in the case of atoms and small clusters, if no optical potential is included. The photo-emission spectrum is derived from the Fourier transform of the single-particle wave-functions. Normal emission 2PPE spectra from Si(001) for s and p-polarized light are presented. We analyze the photon energy and polarization dependence of the theoretical spectra and we compare to experimental 2PPE spectra by Kentsch et al.[1].

[1] C. Kentsch, M. Kutschera, M. Weinelt, T. Fauster, M. Rohlfing, Phys. Rev. B 65, 035323 (2001).