  Two-dimensional topological superconductivity has attracted great interest
due to the emergence of Majorana modes bound to vortices and propagating along
edges. However, due to its rare appearance in natural compounds, experimental
realizations rely on a delicate artificial engineering involving materials with
helical states, magnetic fields and conventional superconductors. Here we
introduce an alternative path using a class of three-dimensional
antiferromagnet to engineer a two- dimensional topological superconductor. Our
proposal exploits the appearance of solitonic states at the interface between a
topologically trivial antiferromagnet and a conventional superconductor, which
realize a topological superconducting phase when their spectrum is gapped by
intrinsic spin- orbit coupling. We show that these interfacial states do not
require fine-tuning, but are protected by asymptotic boundary conditions.
