Regensburg 2007 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 19: Spin controlled transport I
HL 19.3: Vortrag
Dienstag, 27. März 2007, 11:15–11:30, H14
Magnetotransport through nanoscale constrictions in ferromagnetic (001)-(Ga,Mn)As — •Markus Schlapps1, Matthias Döppe1, Stefan Geißler1, Thomas Imlohn1, Janusz Sadowski2, Werner Wegscheider1, and Dieter Weiss1 — 1Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Germany — 2Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
The resistance measured across a small (Ga,Mn)As island detached by nanoconstrictions from (Ga,Mn)As input leads displays unusual magnetoresistance (MR) behavior [1,2]. As in previous studies [1] a huge magnetoresistance was found for nanoconstrictions in the tunneling regime. For slightly wider junctions (on the verge of tunneling) we observed an enhanced anisotropic magnetoresistance together with pronounced jumps as a function of the in-plane magnetic field [3]. This behavior is ascribed to in-plane switching of the magnetization into the easy axis. We investigate the angular dependence of the MR for a tunneling device and discuss the correlation to the TAMR (Tunneling Anisotropic Magneto Resistance) that has been reported previously [2]. In addition we present data of (Ga,Mn)As wires with only one nanoconstriction.
[1] C. Rüster et al.: PRL 91, 216602 (2003)
[2] A. D. Giddings et al.: PRL 94, 127202 (2005)
[3] M. Schlapps et al.: phys. stat. sol. (a) 203, No. 14, 3597 (2006)