Helical spin ordering and interlayer correlations in superlattices

We report neutron-diffraction studies of MnTeCdTe superlattices with extremely thin CdTe spacers. Results indicate the formation of spin helices (consistent with the tensile nature of strain in the MnTe layers) and coherence between the helices in different MnTe layers. Possible mechanisms for the interlayer correlations are discussed.