Modification of terahertz emission spectrum using microfabricated spintronic emitters
Modification of terahertz emission spectrum using microfabricated spintronic emitters
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DOI：
10.1063/5.0013676
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发表时间：
2020-09
影响因子：
3.2
通讯作者：
Wei-Peng Wu;S. Lendínez;Mojtaba Taghipour Kaffash;R. Schaller;H. Wen;M. Jungfleisch
中科院分区：
文献类型：
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作者：
Wei-Peng Wu;S. Lendínez;Mojtaba Taghipour Kaffash;R. Schaller;H. Wen;M. Jungfleisch
亚毫米波福尔斯的太赫兹（THz）辐射介于光频和射频之间的差距。传统的太赫兹发射器不干涉自旋自由度。然而，最近的研究表明，宽带太赫兹辐射也可以通过利用超快时间尺度上的自旋效应来有效地产生。在这里，我们展示了产生和控制太赫兹辐射的微结构自旋太赫兹发射器的基础上的逆自旋霍尔效应。使用时域太赫兹光谱，我们比较了不同的条纹图案的Fe/Pt双层膜与扩展的Fe/Pt双层膜获得的光谱。研究发现，通过适当选择微结构尺寸，可以改变太赫兹光谱。实验观察到的光谱被解释在一个简化的多缝干涉模型，它捕获的主要实验功能。我们的研究结果铺平了道路，一个有效的控制太赫兹光发射的磁性异质结构。这是设计和实现定向太赫兹源的关键一步。
Terahertz (THz) radiation with sub-millimeter wavelength falls in the gap between optical and radio frequencies. Conventional THz emitters do not intertwine with spin degrees of freedom. However, it was recently shown that broadband THz radiation can be efficiently created also by exploiting spin-based effects on ultrafast time scales. Here, we demonstrate the generation and control of THz radiation from microstructured spintronic THz emitters based on the inverse spin-Hall effect. Using time-domain THz spectroscopy, we compare the THz spectra of different stripe patterns made of Fe/Pt bilayers with a spectrum obtained from an extended Fe/Pt bilayer film. It is found that the THz spectrum can be altered by a proper choice of the microstructure dimensions. The experimentally observed spectra are interpreted in terms of a simplified multi-slit interference model, which captures the main experimental features. Our results pave the way for an efficient control of THz light emitted from magnetic heterostructures. This is a crucial step forward for the design and realization of directional THz sources.