Tserkovnyak Yaroslav, Brataas Arne, Bauer Gerrit E W
Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2002 Mar 18;88(11):117601. doi: 10.1103/PhysRevLett.88.117601. Epub 2002 Feb 28.
The precession of the magnetization of a ferromagnet is shown to transfer spins into adjacent normal metal layers. This "pumping" of spins slows down the precession corresponding to an enhanced Gilbert damping constant in the Landau-Lifshitz equation. The damping is expressed in terms of the scattering matrix of the ferromagnetic layer, which is accessible to model and first-principles calculations. Our estimates for permalloy thin films explain the trends observed in recent experiments.
铁磁体磁化的进动被证明会将自旋转移到相邻的正常金属层中。这种自旋的“泵浦”减缓了进动，这对应于朗道-栗弗席兹方程中增强的吉尔伯特阻尼常数。阻尼是根据铁磁层的散射矩阵来表示的，散射矩阵可用于模型和第一性原理计算。我们对坡莫合金薄膜的估计解释了最近实验中观察到的趋势。
