Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
Phys Rev Lett. 2009 Oct 16;103(16):167601. doi: 10.1103/PhysRevLett.103.167601. Epub 2009 Oct 15.
We use spin torque ferromagnetic resonance to measure the spectral properties of dipole-exchange spin waves in Permalloy nanowires. Our measurements reveal that geometric confinement has a profound effect on the damping of spin waves in the nanowire geometry. The damping parameter of the lowest-energy quantized spin-wave mode depends on applied magnetic field in a resonant way and exhibits a maximum at a field that increases with decreasing nanowire width. This enhancement of damping originates from a nonlinear resonant three-magnon confluence process allowed at a particular bias field value determined by quantization of the spin-wave spectrum in the nanowire geometry.
我们使用自旋扭矩铁磁共振来测量坡莫合金纳米线中偶极交换自旋波的谱性质。我们的测量结果表明，几何限制对纳米线中自旋波的阻尼有深远的影响。最低能量量子化自旋波模式的阻尼参数以共振的方式依赖于外加磁场，并在一个随纳米线宽度减小而增加的磁场处呈现最大值。这种阻尼的增强源于在由纳米线几何中的自旋波谱量子化确定的特定偏置场值下允许的非线性共振三磁子汇聚过程。
