SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 7: Poster I

HL 7.61: Poster

Monday, March 27, 2023, 13:00–15:00, P2/EG

Influence of the quantum dot geometry on higher excited states — •Jan Kaspari and Doris E. Reiter — Condensed Matter Theory, TU Dortmund, Otto-Hahn-Straße 4, 44227 Dortmund

The energetic structure and absorption spectra of semiconductor quantum dots are strongly dependent on the dot geometry. In particular the higher excited states, typically denoted as p- or d-shell, can become highly mixed and depend strongly on the specific dot. We derive a theoretical model to describe higher excited quantum dot states based on the envelope function approximation. The four-band Luttinger theory as well as the direct and short-range Coulomb interactions are treated within a configuration interaction approach. The quantum dot confinement is approximated by an anisotropic harmonic potential. We show that a variation of the size of a cylindrical symmetric quantum leads to energetic shifts of higher excited quantum dot states. Breaking this cylindrical symmetry significantly alters the absorption spectrum as further energy splittings in the energetic structure appear and state mixtures change which results in differences of oscillator strenghts of some peaks. Our results give insight into the quantum dot energy structure especially for higher excited states, which become relevant in radiative Auger processes or for ultrafast quantum logic operations.