Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 37: Transport: Nanoelectronics II - Spintronics and Magnetotransport
TT 37.1: Vortrag
Donnerstag, 26. März 2009, 09:30–09:45, HSZ 105
Anisotropic magnetoresistance in ferromagnetic atomic-sized metal contacts — •Michael Häfner1,2, Janne Viljas1,3, and Juan Carlos Cuevas2 — 1Institut für Theoretische Festkörperphysik, Universität Karlsruhe, D-76128 Karlsruhe — 2Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid — 3FZ Karlsruhe, Institut für Nanotechnologie, D-76021 Karlsruhe
Recent experiments in ferromagnetic atomic-sized contacts have shown that the anisotropic magnetoresistance (AMR) is greatly enhanced and has an asymmetric angular dependence as compared with that of bulk samples. The origin of these effects is still under debate. In this work [1] we present a theoretical analysis of the AMR in atomic contacts of the 3d ferromagnetic materials. Our results strongly suggest that the anomalous AMR stems from the reduced symmetry of the atomic contact geometries. We also present calculations supporting the idea that the pronounced voltage- and temperature dependence in some experiments can be attributed to impurities near the constrictions.
[1] M. Häfner et al., arXiv:0811.4491.