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arXiv · 1304.7295

Landau-Lifshitz theory of the longitudinal spin Seebeck effect

Silas Hoffman·Koji Sato·Yaroslav Tserkovnyak
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Abstract

Thermal-bias-induced spin angular momentum transfer between a paramagnetic metal and ferromagnetic insulator is studied theoretically based on the stochastic Landau-Lifshitz-Gilbert (LLG) phenomenology. Magnons in the ferromagnet establish a nonequilibrium steady state by equilibrating with phonons via bulk Gilbert damping and electrons in the paramagnet via spin pumping, according to the fluctuation-dissipation theorem. Subthermal magnons and the associated spin currents are treated classically, while the appropriate quantum crossover is imposed on high-frequency magnetic fluctuations. We identify several length scales in the ferromagnet, which govern qualitative changes in the dependence of the thermally-induced spin current on the magnetic film thickness.

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Silas Hoffman, Koji Sato, Yaroslav Tserkovnyak. 2013-08-12. Landau-Lifshitz theory of the longitudinal spin Seebeck effect. https://doi.org/10.1103/physrevb.88.064408

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