Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 13: Poster 1
HL 13.64: Poster
Montag, 26. März 2007, 15:00–17:30, Poster A
Tunneling anisotropic magnetoresistance effect in a p+-(Ga,Mn)As/n+-GaAs Esaki diode — •Mariusz Ciorga1, Andreas Einwanger1, Janusz Sadowski1,2, Werner Wegscheider1, and Dieter Weiss1 — 1Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany — 2MAX-Lab, Lund University, SE-221 00, Lund, Sweden
We report on the investigation of Tunneling Anisotropic Magnetoresistance effect in single Esaki diode p+-(Ga,Mn)As/n+-GaAs devices in an in-plane magnetic field configuration We performed two types of measurement scans. In the angle scan the value of an external magnetic field H was kept constant while the sample was rotated i.e. the angle between H and the chosen crystallographic axis of (Ga,Mn)As was being changed. This type of scans gave us information about underlying magnetic anisotropy of measured devices. In the field scans the above angle was fixed and the magnetic field was swept from the saturation at one field direction to saturation at the opposite direction. We observed the spin-valve-like signal with the amplitude of ~0.5%. The pattern of the observed magnetic reversal process strongly depends on the observed magnetic anisotropy of the (Ga,Mn)As layer. For samples with an uniaxial anisotropy along [100] directions the sign of the spin-valve-like signal can be changed by a simple rotation of the magnetic field by 90°. This is not the case when device shows an uniaxial anisotropy along [110] directions. The type of the anisotropy is found to be strongly shaped, in a random way, during processing of the wafer.