Abstract

Ultrafast processes of the spin dynamics in iron borate FeBO₃ are considered theoretically; the mechanisms responsible for excitation of quasi-ferromagnetic as well as quasi-antiferromagnetic spin resonance modes by a one-period terahertz pulse are indicated. In full agreement with experimental observations [27], the excitation of the high-frequency quasi-antiferromagnetic mode is resonant by nature, and its amplitude is a linear function of the electric field of the terahertz pulse. The amplitude of the low-frequency quasi-ferromagnetic mode is a quadratic function of the electric field of the pulse, and the excitation of this mode is governed by the mechanism of the inverse Cotton–Mouton effect.

中文翻译：

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硼酸铁易平面弱铁磁体中的超快自旋动力学

摘要

理论上考虑了硼酸铁FeBO ₃中自旋动力学的超快过程。指出了由一个周期的太赫兹脉冲激发准铁磁和准反铁磁自旋共振模式的机理。与实验观察结果完全一致[27]，高频准反铁磁模式的激发本质上是共振的，并且其幅度是太赫兹脉冲电场的线性函数。低频准铁磁模式的振幅是脉冲电场的二次函数，该模式的激发受反棉花-木顿效应机制的控制。