  The topological state of a two-dimensional triplet superconductor may be
changed by an appropriate addition of magnetic impurities. A ferromagnetic
magnetic chain at the surface of a superconductor with spin-orbit coupling may
eliminate the edge states of a finite system giving rise to localized zero
modes at the edges of the chain. The coexistence/competition between the two
types of zero modes is considered. The reduction of the system to an effective
$1d$ system gives partial information on the topological properties but the
study of the two sets of zero modes requires a two-dimensional treatment.
Increasing the impurity density from a magnetic chain to magnetic islands leads
to a finite Chern number. At half-filling small concentrations are enough to
induce chiral modes.
