  Twisted graphene multilayers provide tunable platforms to engineer flat bands
and exploit the associated strongly correlated physics. The two-dimensional
nature of these systems makes them suitable for encapsulation by materials that
break specific symmetries. In this context, recently discovered two-dimensional
helimagnets, such as the multiferroic monolayer NiI$_2$, are specially
appealing for breaking time-reversal and inversion symmetries due to their
nontrivial spin textures. Here we show that this spin texture can be imprinted
on the electronic structure of twisted bilayer graphene by proximity effect. We
discuss the dependence of the imprinted spin texture on the wave-vector of the
helical structure, and on the strength of the effective local exchange field.
Based on these results we discuss the nature of the superconducting
instabilities that can take place in helimagnet encapsulated twisted bilayer
graphene. Our results put forward helimagnetic encapsulation as a powerful way
of designing spin-textured flat band systems, providing a starting point to
engineer a new family of correlated moire states.
