  Chiral magnetic textures are key for the development of modern spintronic
devices. In multilayered thin films, these are typically stabilized via the
interfacial intralayer Dzyaloshinskii-Moriya interaction (DMI). Additionally,
it has been recently observed that DMI may also promote vector spin chirality
along the third dimension, coupling spins in different magnetic layers via
non-magnetic spacer layers, an effect referred to as interlayer DMI (IL-DMI).
This interaction holds promise for 3D nanomagnetism, from the creation of 3D
spin structures such as hopfions to new forms of magnetic functionality in the
vertical direction via remote control of chiral spin states. Here, we
investigate via magnetic X-ray scattering and imaging techniques the chiral
nature of orthogonal magnetic states that form in a synthetic antiferromagnet
with IL-DMI. We find that the vector spin chirality of the textures formed in
an in-plane layer is determined by the net out-of-plane spin configuration of a
neighboring layer, leading as a result to complex spin states across a metallic
interface where the overall scalar spin chirality is preserved. This work thus
uncovers a new flavor of chiral interlayer interactions, demonstrating new ways
to control magnetic chirality in three dimensions.
