  Two different superstructures form when atomic H is incorporated in the Fe
monolayer on Ir(111). Depending on the amount of H provided, either a highly
ordered p(2x2) hexagonal superstructure or an irregular roughly square
structure is created. We present here spin-polarized scanning tunneling
microscopy (SP-STM) measurements which reveal that in both cases the magnetic
nanoskyrmion lattice state of the pristine Fe monolayer is modified. Our
measurements of the magnetic states in these hydrogenated films are in
agreement with superpositions of cycloidal spin spirals which follow the
pattern and the symmetry dictated by the H superstructures. We thus demonstrate
here the possibility to vary the symmetry of a non-collinear magnetic state in
an ultrathin film without changing its substrate.
