  Based on density functional theory combined with low-energy models, we
explore the magnetic properties of a hybrid atomic-thick two-dimensional (2D)
material made of Germanene doped with fluorine atoms in a half-fluorinated
configuration (Ge2F). The Fluorine atoms are highly electronegative, which
induce magnetism and break inversion symmetry, triggering thereby a finite and
strong Dzyaloshinskii-Moriya interaction (DMI). The magnetic exchange
interactions is of antiferromagnetic nature among the first, second and third
neighbors, which leads to magnetic frustration. The N\'eel state is found to be
the most stable state, with magnetic moments lying in the surface plane. This
results from the out-of-plane component of the DMI vector, which seems to
induce an effective in-plane magnetic anisotropy. Upon application of a
magnetic field, spin-spirals and antiferromagnetic skyrmions can be stabilized.
We conjecture that this can be realized via magnetic exchange fields induced by
a magnetic substrate. To complete our characterization, we computed the
spin-wave excitations and the resulting spectra, which could be probed via
electron energy loss spectroscopy, magneto-Raman spectroscopy or scanning
tunneling spectroscopy.
