Hamburg 2001 – wissenschaftliches Programm
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O: Oberflächenphysik
O 13: Postersitzung (Adsorption auf Oberfl
ächen, Oberfl
ächenreaktionen, Elektronische Struktur, Epitaxie und Wachstum, Halbleiteroberfl
ächen und Grenzfl
ächen, Oxide und Isolatoren)
O 13.46: Poster
Montag, 26. März 2001, 19:00–22:00, Foyer zu B
Layer resolved many-body calculations for surfaces of solids — •R. Bahnsen1, W. Schattke1, N. Fitzer2, and R. Redmer2 — 1Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel — 2Fachbereich Physik, Universität Rostock, D-18051 Rostock
To keep up with increasing accuracy and scope of surface experiments as e.g. the measurement of lifetimes at surfaces, systematic improvements in the inclusion of many-body effects at surfaces are necessary[1]. Therefor we apply the Variational quantum Monte Carlo (VMC) scheme to the (110) surface of GaAs. With a finite layer geometry as the boundary condition of integration, the exact many-body Hamiltonian is evaluated in a layer resolved form by two-dimensional Ewald summation technique. Emphasis is laid on the cancellation of all contributions from background charges. The many-body trial wave function is of Slater-Jastrow type with parameterized one-body orbitals and an additional confinement term v which rules the localization of the electrons to the surface system[2]. We compare results for ideal and relaxed surfaces for different system sizes. As a test case for the statistical significance of the method the dangling bond angle and elements of the dynamical matrix are analyzed. Supported by DFG under No. Scha 360/17-1 and Re 882/9-1.
[1] M. Nekovee and J. M. Pitarke, to appear in Comput. Phys. Commun., see preprint arXiv:cond-mat/0012116.
[2] R. Bahnsen, H. Eckstein, W. Schattke, N. Fitzer, and R. Redmer, submitted to Phys. Rev. B, see preprint arXiv:cond-mat/0009147.