Magnetic rare-earth / non-magnetic metal superlattices are well-known to display chiral spin helices in the rare-earth layers that propagate coherently across the non-magnetic layers. However, the underlying mechanism that preserves the magnetic phase and chirality coherence across the non-magnetic layers has remained elusive. In this Letter, we use resonant and element-specific x-ray scattering to evidence directly the formation of two fundamentally different long-range modulations in a Holmium/Yttrium (Ho/Y) multilayer: the known Ho chiral spin helix with periodicity 25 {\AA}, and a newly observed charge density wave with periodicity 16 {\AA} that propagates through both the Ho and non-magnetic Y layer. With x-ray circular magnetic dichroism measurements ruling out the existence of a magnetic proximity effect induced moment in the non-magnetic Y layers, we propose that the charge density wave is also chiral, thus providing the means for the transmittance of magnetic chirality coherence between Ho layers.
@article{arxiv.1909.12372,
title = {Coherent charge and magnetic ordering in Ho/Y superlattice revealed by element-selective x-ray scattering},
author = {V. Ukleev and V. Tarnavich and E. Tartakovskaya and D. Lott and V. Kapaklis and A. Oleshkevych and P. Gargiani and M. Valvidares and J. S. White and S. V. Grigoriev},
journal= {arXiv preprint arXiv:1909.12372},
year = {2019}
}