Regensburg 2010 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 60: Poster II: Optical Properties, incl. Photonic Crystals and Ultrafast Phenomena
HL 60.26: Poster
Thursday, March 25, 2010, 18:00–20:00, Poster D1
Optical signatures of a Bose-Einstein condensate of excitons in a potential trap — •Siegfried Sobkowiak1, Dirk Semkat1,2, Heinrich Stolz1, Thomas Koch2, and Holger Fehske2 — 1Institut für Physik, Universität Rostock, 18051 Rostock — 2Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald
The theoretical description of excitons in traps has been carried out so far mostly in the frame of a model of ideal bosons. In contrast, concepts for the inclusion of the interaction are well known from the theory of atomic condensates [1], first applications to excitons exist, too [2]. Our first investigations in the framework of a mean-field formalism in local density approximation show distinct signatures of a condensate in the decay luminescence spectrum of the non-condensed excitons [3]. Beyond that, we present here a generalization of the theory to a multi-component gas of interacting para- and orthoexcitons [4], where the consequences of the interaction on the condensation process are of particular interest. We show results for the densities of the individual components and their spatially resolved luminescence spectra and compare with experimental data.
[1] N. P. Proukakis and B. Jackson, J. Phys. B 41, 203002 (2008).
[2] L. A. Banyai et al., Phys. Rev. B 70, 045201 (2004).
[3] H. Stolz and D. Semkat, submitted to Phys. Rev. B (2009).
[4] S. Sobkowiak, D. Semkat, H. Stolz, Th. Koch, and H. Fehske, in preparation.