Spin waves and small intrinsic damping in an in-plane magnetized FePt film
Spin waves and small intrinsic damping in an in-plane magnetized FePt film
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DOI：
10.1063/1.4768787
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发表时间：
2012-11
影响因子：
4
通讯作者：
Zhifeng Chen;M. Yi;Ming Chen;Shufa Li;Shiming Zhou;T. Lai
中科院分区：
文献类型：
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作者：
Zhifeng Chen;M. Yi;Ming Chen;Shufa Li;Shiming Zhou;T. Lai
利用全光泵浦-探针磁光克尔光谱研究了不同外场和泵浦影响下平面内磁化FePt薄膜中激光诱导的自旋波动力学。观察到均匀的旋进波。发现了其频率的非线性外场依赖关系，并用均匀进动的宏观自旋模型很好地解释了这一关系。有效阻尼表现出显著的外场依赖性。考虑磁不均匀性的计算结果较好地拟合了外场依赖性，揭示了外阻尼的主要磁不均匀性来源。推导出<0.028的本征吉尔伯特阻尼参数，显示了该薄膜在磁振学中的潜在应用。
Laser-induced spin-wave dynamics in an in-plane magnetized FePt film is studied using all-optical pump-probe magneto-optical Kerr spectroscopy under different external fields and pump fluences. Uniform precession spin wave is observed. Nonlinear external field dependence of its frequency is found and well explained by the macrospin model of uniform precession. The effective damping shows a significant external-field dependence. Calculation taking account for magnetic inhomogeneity fits the external-field dependence well, revealing main magnetic inhomogeneity origin of the extrinsic damping. An intrinsic Gilbert damping parameter of <0.028 is inferred and shows potential applications of this film in magnonics.