  Transition metal halides are quasi-two-dimensional van der Waals magnets that
can potentially host antiferromagnetic (AFM) skyrmions induced by competing
exchange interactions. We study theoretically magnetic states of Fe-doped
NiBr$_2$ using spin interactions obtained by fitting experimental data. We find
that AFM interlayer interactions suppress skyrmion lattices but allow for
skyrmions with topological charges $1,2$ and $3$ confined to a single magnetic
layer. These single-layer skyrmions exist in three different magnetic phases
and their dynamics changes drastically at the transition from a uniform to a
non-collinear modulated state.

Strongly Correlated Electrons