Veranstaltungsdetails

7.9.2010, 17:00
Jungiusstr. 11, Hörsaal AP

SFB 668 - Kolloquium

Yuriy Mokrousov (FZ Jülich):

Anisotropic anomalous Hall effect from first principles

The dissipationless intrinsic anomalous Hall effect (AHE) stemming from non-trivial Berry phases of Bloch electrons in a ferromagnet received much attention lately owing to its possible applications in spintronics and nanoelectronics. In my talk we will apply our recently developed efficient computational methodology to investigating the intrinsic AHE in ferromagnets from the first principles. We will demonstrate that due to a strong dependence of the electronic structure on the magnetization direction in uniaxial crystals the magnitude of the AHE can be altered significantly by rotating the magnetization in a sample, revealing its anisotropic nature [1]. We will predict the magnitude of the AHE anisotropy and explain its origins taking as an example experimentally popular FePt, FePd and FeNi alloys [2]. Further, we will analyze the spin character of the AHE in these compounds, showing that the AHE anisotropy in FePt can be attributed solely to the delocalized spin-flip transitions around the Fermi energy enhanced by strong spin-orbit interaction on Pt atoms. Finally, via employing the Kubo-Streda formalism we will also study the effect of disorder on the AHE anisotropy. Practical applications and experimental ways to observe this anisotropy will be also briefly discussed. [1] E. Roman, Y. Mokrousov, I. Souza, PRL 103, 097203 (2009) [2] K.M. Seemann, Y. Mokrousov, A. Aziz, J. Miguel, F. Kronast, W. Kuch, M.G. Blamire, A.T. Hindmarch, B.J. Hickey, I. Souza and C.H. Marrows, PRL 104, 076402 (2010)