Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 49: Poster II
HL 49.7: Poster
Donnerstag, 27. März 2003, 16:30–19:00, HSZ/P2
Photoluminescence Rings in a Corbino disk under QHE Conditions — •Vít Novák1,2, Pavel Svoboda1, Miroslav Cukr1, Werner Wegscheider2, and Wilhelm Prettl2 — 1Institute of Physics AS CR, Cukrovarnická 10, Prague, Czech Republic — 2Institut für Experimentelle und Angewandte Physik, Universität Regensburg
Modulation doped AlGaAs/GaAs heterojunctions in Corbino disk sample geometry have been cooled down to liquid Helium temperature and homogeneously illuminated by a weak interband light. Band gap photoluminescence of the sample has been imaged onto an IR-sensitive CCD camera. Initially homogeneous photoluminescence becomes spatially modulated, if a strong magnetic field is applied perpendicular to the junction. The modulation has the form of one or more concentric rings which travel across the sample upon changing the magnetic field strength. Clear coincidence can be found between the observed PL-rings and an inhomogeneous electron density redistributed among the Landau levels. This behavior can be understood in terms of a simple model taking into account the presence of an equipotential layer adjacent to the quantum well.