Non-Abelian topological superconductors from topological semimetals and related systems under the superconducting proximity effect

Non-Abelian topological superconductors are characterized by the existence of zero-energy Majorana fermions bound in the quantized vortices. This is a consequence of the nontrivial bulk topology characterized by an odd Chern number. It is found that in topological semimetals with a single two-band crossing point all the gapped superconductors are non-Abelian ones. Such a property is generalized to related but more generic systems which will be useful in the search for non-Abelian superconductors and Majorana fermions.