Ultrafast spin-to-charge conversion in antiferromagnetic (111)-oriented L1₂-Mn₃Ir

Antiferromagnetic L1(2)-Mn3Ir combines outstanding spin-transport properties with magnons in the terahertz (THz) frequency range. However, the THz radiation emitted by ultrafast spin-to-charge conversion via the inverse spin Hall effect remains unexplored. In this study, we measured the THz emission and transmission of a Permalloy/(111)-oriented L1(2)-Mn3Ir multilayer by THz time-domain spectroscopy. The spin Hall angle was determined to be approximately constant at 0.035 within a frequency range of 0.3-2.2 THz, in comparison with the THz spectroscopy of a Permalloy/Pt multilayer. Our results not only demonstrate the potential of L1(2)-Mn3Ir as a spintronic THz emitter but also provide insights into the THz spin transport properties of L1(2)-Mn3Ir.