Regensburg 2010 – scientific programme

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O: Fachverband Oberflächenphysik

O 46: Density functional theory and beyond for real materials I

O 46.10: Talk

Wednesday, March 24, 2010, 12:45–13:00, H34

Electronic excitations in nanostructures: an empirical pseudopotential based approach — •Gabriel Bester — Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany

In this contribution we will outline the framework, based on empirical pseudopotentials and configuration interaction [1], to obtain quantitative predictions of the excited state properties of semiconductor nanostructures using their experimental sizes, compositions and shapes. The methodology can be used to describe colloidal nanostructure of few hundred atoms all the way to epitaxial structures requiring millions of atoms. The aim is to fill the gap existing between ab initio approaches and continuum descriptions. Based on the pseudopotential idea and the developments of empirical pseudopotentials for bulk materials in the early 60’s, the method has evolved into a powerful tool, where the pseudopotential construction has lost some of its empirical character and is now based on density functional theory. We will present the construction of these potentials and the way the ensuing wave functions are used in a subsequent configuration interaction treatment of the excitation. We will illustrate the available capabilities by recent applications of the methodology to unveil new effects in the optics of nanostructures. We will close by an outlook on some envisionned improvements of the method.

[1] G. Bester, J. Phys.: Condens. Matter.21 023202 (2009).