We investigated laser-pulse-induced terahertz (THz) emission in Ta/CoFeB/Ir/CoFeB/Ta layered synthetic magnets with different Ir spacer thicknesses. THz emissions were observed under no applied magnetic fields for samples exhibiting interlayer antiferromagnetic exchange couplings, and those THz emissions also showed oscillatory behavior against the Ir spacer thicknesses. These results are qualitatively explained with the THz emission mechanism due to the inverse spin Hall effect for the laser-induced spin current in the layered structures. We also discuss the effect of a non-collinear configuration of magnetizations on THz emission with macrospin simulation.

中文翻译：

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层状合成磁体的激光诱导太赫兹发射

我们研究了具有不同Ir间隔层厚度的Ta / CoFeB / Ir / CoFeB / Ta层状合成磁体中激光脉冲诱导的太赫兹（THz）发射。在没有施加磁场的情况下，对于表现出层间反铁磁交换耦合的样品，观察到THz发射，并且这些THz发射也表现出针对Ir隔离层厚度的振荡行为。由于层状结构中激光诱导的自旋电流具有逆自旋霍尔效应，因此可以用太赫兹发射机理定性地解释这些结果。我们还讨论了宏旋转模拟的非共线磁化配置对太赫兹发射的影响。