Berlin 2015 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 48: Magnetization / Demagnetization Dynamics IV

MA 48.2: Vortrag

Donnerstag, 19. März 2015, 15:15–15:30, EB 301

Fokker-Planck approach to the theory of magnon-driven spin Seebeck effect — •Levan Chotorlishvili and Jamal Berakdar — Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Heinrich-Damerow-Str. 4, 06120 Halle, Germany

Considering the spin Seebeck effect we calculate the mean value of the total spin current flowing through a normal-metal/ferromagnet interface. The spin current emitted from the ferromagnet to the normal metal is evaluated in the framework of the Fokker-Planck approach for the stochastic Landau-Lifshitz-Gilbert equation. We show that the total spin current depends not only on the temperature difference between the electron and the magnon baths, but also on the external magnetic field and the magnetic anisotropy. In addition, the spin current is shown to saturate with an increasing magnon temperature, and the saturation temperature increases with increasing the magnetic field and/or the magnetic anisotropy. Based on the solution of the stochastic Landau-Lifshitz-Gilbert equation which is discretized for a ferromagnetic chain subject to a uniform temperature gradient, we performed a detailed numerical study of the spin dynamics with a focusing particularly on finite-size effects. Our particular aim was to study the spin Seebeck effect beyond the linear response regime. We find that within our model the microscopic mechanism of the spin Seebeck current is the magnon accumulation effect quantified in terms of the exchange spin torque. // Ref: S. R. Etesami et al Phys. Rev. B 90, 014410 (2014); L. Chotorlishvili et al Phys. Rev. B 88, 144429 (2013).