Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 33: Poster I: Transport, including Magnetic-Field Effects
HL 33.9: Poster
Dienstag, 23. März 2010, 18:30–20:30, Poster D1
Anomalous magnetotransport of magnetic 2DHGs in the quantum-Hall regime — •Stefan Knott1, Ursula Wurstbauer1, Thomas Hirschmann1, Werner Wegscheider2,3, and Wolfgang Hansen1 — 1Institut für Angewandte Physik, Universität Hamburg, Germany — 2Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Germany — 3Solid State Physics Laboratory, ETH Zürich, Switzerland
The interaction of localized magnetic moments with a two-dimensional hole gas is studied with low-temperature magnetotransport measurements. The hole gas is confined in manganese modulation-doped InAlAs/InGaAs/InAs quantum wells grown by molecular beam epitaxy. If Mn ions are inside the quantum well the holes are strongly localized at zero field, while it shows quantized transport at high field featuring Shubnikov-de Haas oscillations and the quantum-Hall effect. Here we present high-field data that show pronounced deviation from the behavior of samples with no Mn ions in the quantum well: The Hall voltage is neither linear nor monotonous and the 1/B-periodicity is not given anymore. Moreover, a significant weak anti-localization signature is present still at 4.2K in samples without Mn ions in the channel, indicating strong spin orbit coupling. The observed temperature dependency of both types of samples and possible explanations will be discussed.