1. Studium terahertzového záření emitovaného pomocí spintronických jevů
- Author
-
Jechumtál, Jiří, Nádvorník, Lukáš, and Kašpar, Zdeněk
- Subjects
spinový Hallův jev ,terahertz radiation ,spintronika ,terahertzové záření ,spin Hall effect ,spintronics ,Physics::Optics - Abstract
Effective emission of picosecond terahertz (THz) pulses using optical femtosecond pul- ses is the basis of THz spectroscopy in the time domain. Recent studies have shown that ultrafast optical excitation of thin metal magnetic multilayers leads to effective emission of THz pulses by converting the spin current to electric current. This work focuses on deter- mining the absolute emission and conversion efficiency of spintronic emitters from several manufacturers. Our comparison suggests that efficiency comparable to highly optimized spintronic emitters can be achieved by utilizing multilayer manufacturing capabilites of the Faculty of Mathematics and Physics of Charles University. The work also demon- strates the significant influence of interface quality on the throughput of ultrafast spin currents. Furthermore, the work describes a saturation effect observed in the relation be- tween emission and optical excitation fluency, which defines suitable excitation conditions for scaling the THz emission to higher electric fields. The observed spectral dependence of emission on fluence complements the discussion about the nature of ultrafast spin current formation. 1
- Published
- 2020