Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 36: Heterostructures
HL 36.2: Vortrag
Donnerstag, 29. März 2007, 10:15–10:30, H14
Quantum Stark confined strongly correlated indirect excitons in quantum wells — •Patrick Ludwig1,2, Alexej Filinov1, Heinrich Stolz2, and Michael Bonitz1 — 1CAU zu Kiel, ITAP, Leibnizstrasse 15, D-24098 Kiel — 2Universität Rostock, Institut für Physik, Universitätsplatz 3, D-18051 Rostock
We consider small ensembles of optically excited indirect excitons (IE) in a single quantum well (QW). Using Path Integral Monte Carlo (PIMC) we compute from first principle the spatial separation of electrons (e) and holes (h) and the lateral quantum Stark confinement of the IE in the QW which is produced by an external electric field of a single tip electrode. [1] In the proposed setup the e-h pairs form permanent dipoles aligned perpendicular to the QW planes. The accompanied repulsive mutual dipole-dipole-like interaction of the IE prevents formation of biexcitons and e-h droplets and masks, at the same time, the fermionic character of the IE constituents, so that the IE are approximately of bosonic nature [2]. By changing the field strength, the tip to sample distance, the excitation intensity (exciton number) and temperature, the IE properties as well as the IE-IE correlations can be varied in broad ranges. Investigating systems of several tens to hundreds of IE in a ZnSe-based QW with PIMC technique we predict the parameter range at which interesting many-particle states, including exciton crystallization should be observable in experiments.[3]
[1] P. Ludwig et al., phys. stat. sol. (b) 243, No. 10 2363-2366 (2006)
[2] A. Filinov et al., phys. stat. sol. (c) 3, No. 7, 2457-2460 (2006)
[3] A. Filinov et al., J. Phys: Conf. Series 35, 197 (2006)