  A major challenge in developing topological superconductors for implementing
topological quantum computing is their characterization and control. It has
been proposed that a p-wave gapped topological superconductor can be fabricated
with single-atom precision by assembling chains of magnetic atoms on s-wave
superconductors with spin-orbit coupling. Here, we analyze the Bogoliubov
quasiparticle interference in atom-by-atom constructed Mn chains on Nb(110) and
for the first time reveal the formation of multi-orbital Shiba bands using
momentum resolved measurements. We find evidence that one band features a
topologically non-trivial p-wave gap as inferred from its shape and
particle-hole asymmetric intensity. Our work is an important step towards a
distinct experimental determination of topological phases in multi-orbital
systems by bulk electron band structure properties only.
