SKM 2021 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 8: Poster Session II

HL 8.23: Poster

Dienstag, 28. September 2021, 10:00–13:00, P

Theoretical description of higher excited quantum dot states in an external magnetic field — •Jan Kaspari, Matthias Holtkemper, Tilmann Kuhn, and Doris Reiter — Institut für Festkörpertheorie, WWU Münster, Wilhelm-Klemm-Straße 10, 48149 Münster, Germany

The influence of a magnetic field on the quantum dot states is usually reduced to the interaction of the external magnetic field with the spins of electrons and holes. Based on the envelope function approximation and minimal coupling we derive additional interaction terms of the magnetic field with the envelope functions and treat the magnetic field interaction, direct and short-range exchange Coulomb interactions as well as the four-band Luttinger theory within a configuration interaction approach. The quantum dot confinement is approximated by an anisotropic harmonic potential. We show that the magnetic field interaction with the envelope functions crucially depends both on the geometry of the quantum dot as well as on the orientation of the magnetic field. In the case of a magnetic field in the growth direction of a cylindrically symmetric quantum dot we find that the interaction with the envelopes results in the mixing of states of the same type which leads to a partial splitting of higher excited energy levels, while for a broken cylindrical symmetry an additional mixing with other orbital states and further energy shifts can be noted. We discuss in detail the observed dependencies on geometric parameters and analyze whether the common approximation to describe the interaction of the external magnetic field solely with spins is applicable for higher excited states.