Volume 113, Number 1, January 2016
|Number of page(s)||6|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||27 January 2016|
Quadexciton cascade and fine-structure splitting of the triexciton in a single quantum dot
1 Faculty of Physics, University of Warsaw - ul. Pasteura 5, 02-093 Warszawa, Poland
2 Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA 25, avenue des Martyrs, 38042 Grenoble, France
Received: 12 October 2015
Accepted: 6 January 2016
We report on the properties of emission lines associated with the cascaded recombination of a quadexciton in single GaAlAs/AlAs quantum dots, studied by means of polarization-resolved photoluminescence and single-photon correlation experiments. It is found that photons which are emitted in a double-step 4X-3X process preserve their linear polarization, similarly to the case of conserved polarization of correlated photons in the 2X-X cascade. In contrast, an emission of either co-linear or cross-linear pairs of photons is observed for the 3X-2X cascade. Each emission line associated with the quadexciton cascade shows doublet structure in the polarization-resolved photoluminescence experiment. The maximum splitting is seen when the polarization axis is chosen along and perpendicular to the  crystallographic direction. This effect is ascribed to the fine-structure splitting of the exciton and triexciton states in the presence of an anisotropic confining potential of a dot. We also show that the splitting in the triexciton state surpasses that in the exciton state by a factor up to eight and their ratio scales with the energy distance between the 3X and X emission lines, thus, very likely, with a lateral size and/or a composition of the dot.
PACS: 71.35.-y – Excitons and related phenomena / 78.67.Hc – Quantum dots / 71.70.Gm – Exchange interactions
© EPLA, 2016
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.