Researchers from the Service de Physique de l’État Condensé (SPEC – CEA), in collaboration with the Laboratoire Albert Fert (CNRS-Thales), the SPMS Laboratory (CentraleSupélec-CNRS), have demonstrated for the first time that an ultrafast spin current can efficiently transfer spin angular momentum into an insulating antiferromagnet and trigger its coherent terahertz magnetic excitations. This breakthrough overcomes…