Dresden 2009 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 37: Transport: Nanoelectronics II - Spintronics and Magnetotransport

TT 37.1: Talk

Thursday, March 26, 2009, 09:30–09:45, HSZ 105

Anisotropic magnetoresistance in ferromagnetic atomic-sized metal contacts — •Michael Häfner^1,2, Janne Viljas^1,3, 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.