1. The authors provide a novel approach aimed toward the demonstration of non-Abelian fusion rules of Majorana fermions in setups that may be in experimental reach in the foreseeable future. In contrast to most previous approaches where localized Majorana bound states have been considered, the authors adopt a novel viewpoint and study edge vortices in systems with chiral Majorana edges. In such a system the injection of vortices at opposite ends amounts to a nonlocal encoding of fermion parity. This idea may have certain advantages over other proposals but of course may also turn out to have disadvantages on its own. Nevertheless, I believe that in view of the current status of the field (where even basic Majorana fusion experiments are missing, or the very existence of Majorana bound states remains hotly debated) a new promising proposal such as the one presented here is more than welcome.
2. The paper is nicely written and fun to read. Even people not working directly in the field can understand it.
3. Methodologically, the scattering approach and the Klich formula are here considered for Majorana systems. The results can then be obtained by analysis of Toeplitz determinants, and allow even for analytical results.
4. Detection of fusion could be possible in their scheme by measuring currents and their shot noise. This simplicity is a big advantage.