Novel Surface States of a Spinor Superconductor

Recently, Berry phase enforced spinor superconducting orders have been proposed arising from pairing topological Fermi surfaces with their Chern numbers differing by an odd integer. This exotic pairing structure can exhibit a single pairing gap node on a Fermi surface and is described by monopole harmonics with half-integer charge and fractionalized half-integer partial-wave symmetry. We investigate topologically protected surface states in a simplest example of spinor pairing with pair monopole charge q|| = ½ when spineless fermions in a topological trivial Fermi surface pair with spin-½ electrons in a helical Fermi surface with Chern number -1 under hard-core interaction between them. We find exotic non-majorana states localized at surfaces of the system protected by the topological spinor superconducting order.