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MA: Fachverband Magnetismus
MA 43: Magnetization / Demagnetization Dynamics III
MA 43.4: Vortrag
Donnerstag, 19. März 2015, 10:15–10:30, EB 301
Phonon-affected Gilbert damping tensor within the breathing Fermi-surface model — •Danny Thonig1, Nicki F. Hinsche2, Jürgen Henk2, and Olle Eriksson1 — 1Department of Material Theory, Uppsala University, Sweden — 2Martin Luther University Halle-Wittenberg, Halle, Germany
Concerning magnetic switching, an essential property of magnetic devices is the relaxation rate which depends strongly on the damping α in the magnetization dynamics. This angular-momentum dissipation was predicted to be dominated by the coupling between the magnon and the phonon reservoir [1]. Especially in the high-temperature regime, discrepancies between theory and experiment call for deeper understanding of the phonon-mediated damping, for example by means of a model.
We apply the breathing Fermi-surface model [2] in the framework of a Green-function tight-binding approach [3] and transition matrix theory. For bulk Stoner magnets, the spatial disorder (phonons) is considered either as gaussian-distributed around the equilibrium positions or as a self-energy. We compare these two approaches with each other, with other ab initio methods as well as with experiment.
[1] H. Ebert, S. Mankovsky, D. Ködderitzsch, and P. J. Kelly., Phys. Rev. Lett, 107 (2011) 066603
[2] V. Kamberský, Cz. Journal of Physics B, 34 (1984) 1111
[3] D. A. Papaconstantopoulos and M. J. Mehl, J. Phys.: Condens. Matter, 15 (2003) R413-R440