Science Advances, 7 Nov 2025, Vol 11, Issue 45

In the context of THz spintronics,antiferromagnets have clearly a pivotal role in transport and processing ofspin information, standing as key components in addressing ultrafast spintronicchallenges. However, one crucial issue has remained unresolved: thedemonstration of the ultrafast transfer of spin information toantiferromagnetic dynamics, i.e. at picosecond and sub-picosecond timescales. Thisstudy is filling this gap by employing an experimental approach based oncutting-edge time-resolved magneto-optical and birefringence measurements on aprototypical single-domain insulating magneto-electric antiferromagnet thinfilm. The experimental observations have evidenced that THz antiferromagneticdynamics in the insulating antiferromagnet could be efficiently triggered bythe light-induced ultrafast dynamics of an adjacent ferromagnetic layer,playing the role of the ultrafast spin current generator. We conclude that theobserved THz oscillations were indeed hosted in the AF insulator thanks to acomplex set of angular dependences. In this work, we thus demonstrate thatmagnetic information can indeed be propagated into antiferromagnetic spin wavesat picosecond timescales, thereby opening an avenue towards ultrafastmanipulation of magnetic information.