This work demonstrates exciton transport driven by spin excitations in the van der Waals antiferromagnetic semiconductor CrSBr. Ultrafast exciton propagation with effective diffusion coefficients exceeding classical expectations is observed using time-resolved optical microscopy. The transport exhibits strong dependence on magnetic order, with a pronounced maximum at the Néel temperature. Experimental observations reveal nearly isotropic propagation, transient contraction of exciton clouds at low temperatures, and superdiffusive behaviour in bilayer samples. The results are explained by magnon–exciton drag arising from scattering between excitons and thermally excited magnons. These findings highlight a mechanism to control quasiparticle transport using spin excitations, linking excitonics with spintronics and magnetotransport phenomena.
Dirnberger et al. (Fri,) studied this question.