Departamento de Física, Universidade Federal de Pernambuco, Recife, PE 50670-901, Brazil.
Phys Rev Lett. 2011 Nov 4;107(19):197203. doi: 10.1103/PhysRevLett.107.197203.
We observe amplification of spin-wave packets propagating along a film of single-crystal yttrium iron garnet subject to a transverse temperature gradient. The spin waves are excited and detected with standard techniques used in magnetostatic microwave delay lines in the 1-2 GHz frequency range. The amplification is attributed to the action of a thermal spin-transfer torque acting on the magnetization that opposes the relaxation and which is created by spin currents generated through the spin-Seebeck effect. The experimental data are interpreted with a spin-wave model that gives an amplification gain in very good agreement with the data.
我们观察到沿单晶钇铁石榴石薄膜传播的自旋波包的放大，该薄膜受到横向温度梯度的影响。自旋波是通过在 1-2 GHz 频率范围内使用静磁微波延迟线中的标准技术来激发和检测的。放大归因于作用在与弛豫相反的磁化强度上的热自旋转移扭矩的作用，该扭矩是通过通过自旋塞贝克效应产生的自旋电流产生的。实验数据通过自旋波模型进行解释，该模型给出的放大增益与数据非常吻合。
