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HL: Halbleiterphysik

HL 17: Symposium Quantenringe

HL 17.1: Talk

Tuesday, March 25, 2003, 11:00–11:30, POT/81

Self-Organized InGaAs Quantum Rings — Fabrication and Spectroscopy — •Axel Lorke — Laboratorium für Festkörperphysik, Gerhard-Mercator-Universität Duisburg, Lotharstr. 1, 47048 Duisburg

When InAs islands, grown by Stranski-Krastanov self-organization, are covered by a thin GaAs layer, a remarkable morphological transformation takes place, which results in the formation of self-organized InGaAs rings. When these rings are incorporated in a suitable field-effect transistor structure, they can controllably be filled with 1–3 electrons each, which are in the true, scatter-free quantum limit.

In the first part, this talk will focus on the materials science aspects of InGaAs growth that leads to the remarkable change in topography from dots to rings. The second part will deal with the electronic properties of not simply-connected quantum systems in high magnetic fields, e.g. the formation of a single-electron ground state with non-vanishing angular momentum. Also, new developments in the wave-function mapping of quantum dots and rings will be discussed.