Efficiency of ultrafast optically induced spin transfer in Heusler compounds

Optically induced spin transfer (OISTR) is a pathway to control magnetization dynamics in complex materials on femto-to attosecond timescales. The direct interaction of the laser field with the material creates transient nonequilibrium states, which can exhibit an efficient spin transfer between different magnetic subsystems. How far this spin manipulation via OISTR is a general phenomenon or restricted to a subset of materials with specific properties is an open experimental and theoretical question. Using time-resolved magneto-optical Kerr measurements and time-dependent density functional theory we investigate OISTR in Heusler compounds. We show that the half-Heusler materials NiMnSb and CoMnSb exhibit strong signatures of OISTR, whereas this is less pronounced in the full-Heusler compounds Co2MnSi, Co2FeSi, and Co2FeAl in agreement with ab initio calculations. Our work opens up a systematic path for coherent manipulation of spin dynamics by direct light-matter interaction.