Spin-transfer torque based damping control of parametrically excited spin waves in a magnetic insulator
Spin-transfer torque based damping control of parametrically excited spin waves in a magnetic insulator
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DOI：
10.1063/1.4939268
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发表时间：
2015-08
影响因子：
4
通讯作者：
V. Lauer;D. Bozhko;D. Bozhko;T. Brächer;P. Pirro;V. Vasyuchka;A. Serga;M. Jungfleisch;M. Agrawal-M.-Ag
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文献类型：
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作者：
V. Lauer;D. Bozhko;D. Bozhko;T. Brächer;P. Pirro;V. Vasyuchka;A. Serga;M. Jungfleisch;M. Agrawal-M.-Ag
在磁性绝缘体Yttrium Iron Garnet(YIG)中参变激发的自旋波的衰减是由通过相邻正常金属膜的直流电流控制的。实验是在横向尺寸为4×2mm2的宏观尺寸的YIG(100 Nm)/Pt(10 Nm)双层膜上进行的。自旋波弛豫频率由布里渊光散射谱测量的参数不稳定性阈值来确定。在铂薄膜上施加直流电流，由于自旋霍尔效应，形成垂直于薄膜平面的自旋极化电子电流。这种自旋电流在YIG薄膜中施加了自旋转移扭矩，从而改变了自旋波的衰减。根据施加的直流电流相对于磁化方向的极性，可以增加或减少衰减。其变化的大小与施加的电流成正比。在外加电流密度为……的情况下，弛豫频率的变化为±7.5%。
The damping of spin waves parametrically excited in the magnetic insulator Yttrium Iron Garnet (YIG) is controlled by a dc current passed through an adjacent normal-metal film. The experiment is performed on a macroscopically sized YIG(100 nm)/Pt(10 nm) bilayer of 4 × 2 mm2 lateral dimensions. The spin-wave relaxation frequency is determined via the threshold of the parametric instability measured by Brillouin light scattering spectroscopy. The application of a dc current to the Pt film leads to the formation of a spin-polarized electron current normal to the film plane due to the spin Hall effect. This spin current exerts a spin transfer torque in the YIG film and, thus, changes the spin-wave damping. Depending on the polarity of the applied dc current with respect to the magnetization direction, the damping can be increased or decreased. The magnitude of its variation is proportional to the applied current. A variation in the relaxation frequency of ±7.5% is achieved for an applied dc current density of...