Unconventional Majorana fermions on the surface of topological superconductors protected by rotational symmetry

Topological superconductors are exotic gapped phases of matter hosting Majorana mid-gap states on their boundaries. In conventional three-dimensional topological superconductors, in-gap appear in the form spin-1/2 fermions with a quasirelativistic dispersion relation. Here, we show that unconventional can emerge surface protected by rotational symmetry. The classified into three different categories: spin-$s$ fermion $(2s+1)$-fold degeneracy $(s\ensuremath{\ge}3/2)$, Fermi line carrying two distinct charges, and quartet related fourfold spectral properties first types, which go beyond fermions, unique to have no counterparts insulators. We be obtained superconducting phase doped ${Z}_{2}$ insulators or Dirac semimetals