On-line SPICE-SPIN+X Seminars

On-line Seminar: 31.01.2024 - 15:00 CET

Terahertz spinorbitronics - driving and probing spin and orbital currents at highest frequencies

Tom Seifert, FU Berlin

Launching terahertz (THz) angular-momentum currents from a magnet into a nearby material can be accomplished by laser-induced ultrafast magnetization quenching. Two channels for those ultrafast currents can be distinguished: spin and orbital angular momentum, i.e, S and L, respectively. In my talk, I will focus on the generation, propagation and detection of such laser-induced THz S and L currents in prototypical thin-film heterostructures. In detail, I will show how THz emission spectroscopy led to the development of efficient spintronic terahertz emitters relying on the spin degree of freedom [1,2]. Recently, an inversion of this emitter principle allowed for a broadband spintronic terahertz detection [3]. Finally, I will show how this experimental technique helped revealing THz L currents with a giant decay length in tungsten [4], and enabled us to measure THz spin conductances of antiferromagnetic insulators.

[1] Seifert, Tom, et al. "Efficient metallic spintronic emitters of ultrabroadband terahertz radiation." Nature photonics 10 (2016).
[2] Seifert, Tom S., et al. "Spintronic sources of ultrashort terahertz electromagnetic pulses." Applied Physics Letters 120 (2022).
[3] Chekhov, A. L., et al. "Broadband spintronic detection of the absolute field strength of terahertz electromagnetic pulses." Physical Review Applied 20 (2023).
[4] Seifert, Tom S., et al. "Time-domain observation of ballistic orbital-angular-momentum currents with giant relaxation length in tungsten." Nature Nanotechnology 18 (2023).

Please sign up here in order to get the Zoom link and regular announcements of the upcoming talks.

PDF file of the talk available here