Regensburg 2013 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 45: Transport in high magnetic fields / Quantum Hall effect
HL 45.3: Vortrag
Dienstag, 12. März 2013, 15:30–15:45, H13
Magnetoresistance studies on two-dimensional electron gases in GaAs/AlGaAs heterostructures as a tool for sample quality investigation — •Eddy P. Rugeramigabo1,2, Lina Bockhorn1, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Abteilung Nanostrukturen, Leibniz Universität Hannover, Deutschland — 2QUEST Centre for Quantum Engineering and Space-Time Research, Leibniz Universität Hannover, Deutschland
Several GaAs/AlGaAs heterostructures of similar mobility have been grown by molecular beam epitaxy. The two-dimensional electron gases are located in single GaAs quantum wells. The samples were grown with the same layer sequence but under different growth conditions. Despite the similar mobility, we observed differences in the quantum Hall effect measurements. At small magnetic fields we found in all samples parabolic negative magnetoresistances. This is an indication for electron-electron interaction under influence of disorder. The curvatures of the parabolic magnetoresistance are different, as well as their temperature dependences. The parabolic magnetoresistance has been used as a tool to characterize the quality of the heterostructures.