Spin Signature of Majorana Fermions in Topological Nodal-Point Superconductors

We highlight a situation having attracted little attention previously that in two-dimensional topological nodal superconductors, the Majorana edge states with breaking chiral symmetry but preserving nearly flat bands can have unexpected spin-singlet component of pairing correlations compared with the counterparts of exactly flat bands. Moreover, it is detectable by means of spin-selective Andreev reflection in a realistic topological nodal superconductor with antiferromagnetism, as the conductance peaks become the most outstanding when the spin polarization of incident electrons is (approximately) antiparallel to that of Majorana edge excitations. Therefore, our findings uncover another previously unexpected spin-dependent scenario for the Andreev reflection resonant peaks, and the related features constitute an important step forward in the quest for experimental detection of Majorana fermions in a system with the same kind of topological superconductivity.