  Interfacial Dzyaloshinkii-Moriya interaction defines a rotational sense for
the magnetization of two-dimensional films making it responsible for the
formation of chiral magnetic structures like spin-spirals and skyrmions in
those films. Here we show by means of atomistic calculations that in
heterostructures magnetic layers can be additionally coupled by an interlayer
Dzyaloshinskii-Moriya interaction across a spacer. We quantify this interaction
in the framework of the Levy-Fert model for trilayers consisting of two
ferromagnets separated by a non-magnetic spacer yielding non-trivial
three-dimensional spiral states across the trilayer. This analysis enables
three-dimensional tailoring of the magnetization chirality in magnetic
multilayers.
