Fig. 4: Inverse spin-Hall effect-based THz emission.

a Schematic of an ISHE-based THz emitter, which converts the ultrafast laser-induced spin current in the FM layer into a charge current in the NM layer. b Contrasting interfacial spin accumulation from Ru and Au metallic layers showing the comparatively rapid equilibration in the Au system. c THz radiation from Fe/Ru and Fe/Au emitters showing the dramatically larger emission bandwidth of the latter. d Schematic of THz emission from [Co/Pd]/Mn₂Au structure where the spin-polarized current is generated in the Co/Pd layer and the sublattice-mediated reorientation of spins in the AFM Mn₂Au generates a THz pulse polarized along the direction of magnetization. e Illustration of the spin-to-charge current conversion in an AFM, which drives a spin reorientation of out-of-plane polarized spins into antiparallel in-plane direction in the two magnetic sublattices yielding a charge current due to shifting of the Fermi contour. f THz transient from the [Co/Pd]/Mn₂Au emitter showing phase reversal under the change of external magnetic field orientation. Panels (b, c) reprinted with permission from ref. ⁵³ © 2013 Nature Publishing Group. Panels (d–f) reprinted with permission from ref. ¹²⁹ © 2022 Wiley-VCH GmbH