Abstract
A combined analysis of microphotoluminescence () and microphotoluminescence excitation () spectra of the same single quantum dot (QD) enables an unambiguous identification of four sharp resonances in the excitation spectrum detected on the positive trion transition and reveals the complete fine structure of the hot trion. Transitions into states normally forbidden by (spin) selection rules for optical transitions between pure spin states are observed. The splittings of all triplet states are found to be large (up to 3 meV), asymmetric, and QD size and shape dependent. The experimental data are in excellent agreement with theoretical calculations in the framework of eight-band theory and the configuration-interaction method. To account for the physical effects which lead to the observed fine-structure splitting, parts of the complex model are successively omitted. This approach identifies the anisotropic hole-hole exchange interaction as well as correlation effects dominating the observed fine-structure splitting of the hot trion.
- Received 5 December 2008
DOI:https://doi.org/10.1103/PhysRevB.79.125316
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