Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 31: Poster I: Devices, Quantum Dots and Quantum Wires

HL 31.24: Poster

Tuesday, March 23, 2010, 18:30–20:30, Poster D1

Magnetotransportmeasurements on epitaxially grown GaAs/(Ga,Mn)As core-shell nanowires — •Christian Butschkow, Stefan Geissler, Silvia Schmidmeier, Andreas Rudolph, Dieter Schuh, Elisabeth Reiger, Matthias Kießling, Christian Back, and Dieter Weiss — Institut für Experimentelle und Angewandte Physik , Universität Regensburg, Deutschland

We performed magnetotransport measurements on epitaxially grown GaAs/(Ga,Mn)As core-shell nanowires to investigate the magnetic anisotropies of individual nanowires. We found an uniaxial anisotropy with a magnetic hard axis perpendicular to the axis of the nanowire in agreement with SQUID characterizations done on an ensemble of identically grown nanowires. Depending on the direction of magnetization with respect to the nanowire axis, a single domain-switching process takes place at applied fields between 200 mT (parallel configuration) and 1.7 T (near perpendicular configuratian). For saturating the nanowire in the perpendicular configuration a magnetic field of more than 3 T is required. Sweeping the applied magnetic field to high values we observe a rather high negative magnetoresistance if compared to(Ga,Mn)As-films. Furthermore, we determined a Curie-Temperature of about 18K by transport measurements, which is consistent with the results of the SQUID characterizations.