Nonlinear scattering in nanoscale magnetic elements: Overpopulation of the lowest-frequency magnon state
Nonlinear scattering in nanoscale magnetic elements: Overpopulation of the lowest-frequency magnon state
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DOI：
10.1103/physrevb.83.020404
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发表时间：
2011-01-11
影响因子：
3.7
通讯作者：
Urazhdin, Sergei
中科院分区：
文献类型：
--
作者：
Demidov, Vladislav E.;Ulrichs, Henning;Urazhdin, Sergei
利用布里渊光散射技术研究了微波强磁场驱动下纳米坡莫合金元件的磁化动力学。我们表明，在大的旋进角，由微波激发的磁振子散射到最低频率状态的散射，导致玻色-爱因斯坦凝聚的磁振子在低损耗石榴石膜的过程类似。这一发现对于理解强驱动纳米磁器件（如自旋力矩纳米振荡器和磁存储器）中的非线性过程非常重要。
We utilized Brillouin light-scattering spectroscopy to study the magnetization dynamics in nanoscale permalloy elements driven by a large microwave magnetic field. We demonstrate that at large precession angles, the magnons excited by the microwaves scatter into the lowest-frequency state by a process similar to the scattering that leads to the Bose-Einstein condensation of magnons in the low-loss garnet films. The discovered effect is important for understanding the nonlinear processes in strongly driven nanomagnetic devices such as spin-torque nano-oscillators and magnetic memory.