Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 31: Poster II
HL 31.9: Poster
Dienstag, 26. Februar 2008, 16:30–19:00, Poster D
Magnetotransport through lateral (001)-(Ga,Mn)As structures with nanoconstriction — •Markus Schlapps1, Teresa Lermer1, Daniel Neumaier1, Rashid Gareev1, Janusz Sadowski2, Werner Wegscheider1, and Dieter Weiss1 — 1Institut für Experimentelle und Angewandte Physik , Universität Regensburg, Germany — 2Max-Lab, Lund University, Sweden
The resistance measured across a small (Ga,Mn)As island detached by nanoconstrictions from (Ga,Mn)As input leads displays unusual magnetoresistance (MR) behavior [1,2,3]. In previous studies [1,3] a huge magnetoresistance was found for nanoconstrictions in the tunneling regime. We have already reported on investigations of the angular dependence of the MR in such double-constricted devices and discussed its correlation with the Tunneling Anisotropic Magneto Resistance (TAMR) effect [4]. Here we focus on MR measurements carried out on (Ga,Mn)As wires with only one nanoscale constriction. Samples with different constriction-resistances are compared. Strongly nonlinear I-V characteristics depending on the magnetization orientation have been observed for a high resistive sample that also shows very large MR-effects of up to 6000%. We discuss the possibility of a metal-insulator transition being responsible for the observed effects.
[1] C. Ruester 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) [4] M. Ciorga et al: New J. Phys. 9, 351 (2007)